THE BATTLE FOR THE SEA LANES

In 1906 the British launched HMS Dreadnought, a battleship armed with ten 12-inch guns and driven by steam turbines, and in one stroke made every earlier battleship obsolete. Germany, which had begun its own naval expansion in 1898 under Admiral Alfred von Tirpitz, answered by building dreadnoughts of its own, and the Anglo-German naval race that followed is one of the causes of the war (see chapter I). Tirpitz's "risk theory" held that a German fleet strong enough to hurt the Royal Navy badly in battle would deter Britain from fighting at all. By August 1914 the plan had not worked: Britain still held a lead of roughly three to two in modern capital ships, and a much larger one in cruisers and destroyers, and it had entered the war anyway.

The Royal Navy's wartime strategy was therefore defensive in an unusual sense. It did not need to destroy the German fleet; it needed to prevent it from interfering with British trade and from helping an invasion, and to keep the sea lanes open. The Grand Fleet, under Admiral Sir John Jellicoe, was based at Scapa Flow in the Orkney Islands, a vast natural anchorage which closed the northern exit of the North Sea. Battlecruisers under Vice-Admiral David Beatty were later based at Rosyth on the Firth of Forth, and smaller forces at Harwich and Dover watched the narrow seas in the south. Churchill, who as First Lord of the Admiralty was a keen student of these matters, wrote later that Jellicoe was the only man on either side who could lose the war in an afternoon: if the Grand Fleet were destroyed, Britain's blockade, its armies' supplies and its food would be at the mercy of the enemy.

For Germany, the question was how to use a fleet that was strong but not strong enough. The High Seas Fleet was concentrated at Wilhelmshaven and Cuxhaven, and the Kaiser, who adored his ships, did not want them risked. The doctrine that emerged is called a "fleet in being": the mere existence of a force obliges the enemy to keep a larger force in readiness to meet it, even if it never sails. German leaders hoped to whittle down British strength with mines, submarines and raids until a battle became possible on better terms. Raids on the English coast, such as the bombardment of Scarborough, Hartlepool and Whitby on 16 December 1914, which killed more than a hundred civilians, were meant to draw out a detachment of the Grand Fleet that could be ambushed. A well-informed British Admiralty nearly sprang a trap of its own, but the raiders escaped in poor visibility.

The first lessons

The early weeks of the war taught both navies how vulnerable their big ships were. On 22 September 1914 a single German submarine, U-9 under Otto Weddigen, sank three old British armored cruisers, Aboukir, Hogue and Cressy, within about an hour off the Dutch coast, killing nearly 1,500 men. A few weeks later the new British dreadnought Audacious struck a mine and sank. After a submarine scare in October the Grand Fleet was moved temporarily to the west coast of Scotland and Ireland, and in November a German submarine, U-18, slipped into Scapa Flow, found it almost empty, and was rammed and lost on the way out. Nets, booms and blockships made the base secure. Admirals on both sides drew the same conclusion: the capital ship, now worth tens of millions of pounds, had become hostage to the mine and torpedo, and had to be kept out of reach of them. The result was a war in which the world's most powerful fleets avoided each other for long stretches, while smaller craft fought a ferocious war of attrition around them.

International law before 1914 allowed a blockading navy to patrol directly off an enemy's ports and to seize contraband. Britain knew that such a "close" blockade of Germany was out of the question: the German coast was guarded by mines, submarines and torpedo boats that would massacre a blockading squadron. The Admiralty chose a "distant" blockade instead, closing the two exits of the North Sea: the Dover Strait in the south, and the wide waters between Scotland, the Shetlands and Norway in the north, patrolled by the Northern Patrol, a force of old cruisers and armed merchant liners. Neutral ships were stopped, searched and often sent into British ports for inspection. Over the first two years the rules were steadily tightened. In March 1915 an Order in Council announced that goods of German origin or destination were liable to seizure; foodstuffs were added to the list of contraband, and cotton (to the anger of the American South) in August 1915. A Ministry of Blockade was created in February 1916 under Lord Robert Cecil.

The blockade could work only if neutral countries were prevented from becoming a back door. Britain therefore negotiated agreements with Dutch and Scandinavian traders, rationed neutral imports to their pre-war levels, and later introduced "navicerts", certificates that allowed cargoes of approved goods to pass the patrols. The Americans, whose trade with Germany shrank while their exports to the Allies boomed, protested again and again at British interference, though much less sharply than at German submarine attacks. Germany described the blockade as a deliberate "hunger blockade", and many German civilians came to believe it.

Germany had been a large importer of food, animal feed and fertilizer before the war, as well as of nitrates, copper, rubber, cotton and oil. The blockade cut off these imports, but not all at once, and its effects were compounded by the war itself: the army took millions of farmers and farm horses, the supply of fertilizer fell, and in 1916 a wet autumn ruined the potato crop. The result was the "Turnip Winter" of 1916 to 1917, in which turnips and swedes replaced potatoes and bread was mixed with fillers. Official rations were far below peacetime levels, and a black market flourished. There were hunger riots, and in April 1917 hundreds of thousands of workers struck in Berlin, Leipzig and other cities. A second, bleaker winter followed in 1917 to 1918, and by 1918 many German children were underweight. After the war, German statistical offices estimated the number of excess civilian deaths in the hundreds of thousands; estimates range from about 400,000 to over 700,000, and the exact figure is much debated, because it is hard to separate the effect of the blockade from that of influenza and general wartime dislocation.

Effects on the Allies and neutrals

The mirror image of the German blockade was the Allied dependence on the sea. Britain imported roughly 60 percent of its food, including most of its wheat, as well as many of its raw materials, and had to move millions of men and many millions of tons of munitions to France, the Mediterranean and the Middle East. Russia's position was worse: in the autumn of 1914 the Ottoman Empire closed the Dardanelles, and Germany controlled the Baltic, so Russia's grain exports ended and her imports of munitions had to travel by distant Arctic and Pacific ports and over a primitive railway. The Allied failure to open the Straits at Gallipoli was thus a naval and economic failure as well as a military one (see chapter IV).

Neutrals suffered in between. Dutch, Danish, Norwegian and Swedish merchants made large profits from the trade and also lost ships and sailors to both sides' mines and submarines. By the end of the war a naval war which had begun with two navies looking for decisive battle had turned into a war between economies, with each side trying to destroy the other's capacity to import. It was in this context that Germany turned to the submarine.

When war began, the Royal Navy faced a problem scattered across the oceans: a handful of German warships that could, if left alone, prey on the British Empire's commerce. The most powerful of them was Vice-Admiral Maximilian von Spee's East Asia Squadron, based at the Chinese port of Tsingtao: the two modern armored cruisers Scharnhorst and Gneisenau, and the light cruisers Nürnberg, Leipzig and Emden. Spee knew he could not hope to hold Tsingtao against the Japanese, who entered the war on the Allied side on 23 August and besieged the base (it fell on 7 November), so he took his squadron across the Pacific, hoping to reach Germany or at least to do as much damage as possible on the way.

Coronel and the Falklands

On 1 November 1914 Spee met a weaker British squadron under Rear-Admiral Sir Christopher Cradock off Coronel on the coast of Chile. Cradock, who had been sent with obsolete ships and a hastily gathered crew, chose to fight rather than retreat. The sun set behind the British, outlining them against the horizon, while Spee's ships were in darkness, and the German gunners were far better trained. In under an hour the armored cruisers Good Hope and Monmouth were sunk with all hands, about 1,600 men, including Cradock. It was the first British naval defeat in a century.

The Admiralty's reaction was swift. First Sea Lord Lord Fisher sent two battlecruisers, Invincible and Inflexible, under Vice-Admiral Sir Doveton Sturdee, across the Atlantic in secret. They reached the Falkland Islands on 7 December, one day before Spee, who had decided to raid the coaling station at Port Stanley, appeared on the horizon. Seeing tripod masts over the land, he realized what he faced and ran. The battlecruisers, with their 12-inch guns and higher speed, ran him down in the long afternoon of 8 December. Scharnhorst, Gneisenau, Nürnberg and Leipzig were sunk; Spee died with them, as did his two sons, who were serving in the squadron. Nearly 1,900 German sailors died. Only the light cruiser Dresden escaped, to hide for three months in the Chilean fjords until she was caught and scuttled in March 1915. The oceans were all but cleared of German warships.

Emden

Meanwhile the light cruiser Emden, detached by Spee in August, had made a name for herself in the Indian Ocean. Under Captain Karl von Müller, who treated his captives with courtesy, she sank or captured 17 merchant ships, bombarded the oil tanks at Madras on 22 September, and slipped into the harbor of Penang on 28 October to sink a Russian cruiser and a French destroyer. For two months dozens of Allied warships hunted her. On 9 November 1914 she approached the Cocos (Keeling) Islands to destroy the cable station, where the Australian cruiser HMAS Sydney, escorting a troop convoy, caught her. Sydney's heavier guns pounded the German ship until she ran herself aground, with 134 dead. A landing party under Lieutenant Hellmuth von Mücke escaped in a schooner and made its way to Constantinople by way of Arabia, an adventure much celebrated in Germany.

Königsberg in the delta

In East Africa the light cruiser Königsberg sank the British cruiser Pegasus at Zanzibar on 20 September 1914 and then took refuge in the maze of channels at the mouth of the Rufiji River in what is now Tanzania. The Royal Navy, unable to reach her, blockaded the delta for nine months. Aircraft eventually spotted the fall of shot for two shallow-draft monitors, Severn and Mersey, which destroyed her on 11 July 1915. Her crew salvaged her guns, hauled them inland, and joined the little army of Colonel Paul von Lettow-Vorbeck; the naval guns, mounted on improvised carriages, served the German army in East Africa for years (see chapter XIII).

The submarine was the weapon of the weaker navy and, as it turned out, the one that came closest to deciding the war. German U-boats were small, slow and fragile: a typical boat of 1914 displaced about 700 tons, carried four torpedo tubes and a deck gun, made about 16 knots on the surface and 10 submerged, and spent most of its time on the surface to save its batteries. But a handful of them could do more damage to enemy shipping than a whole squadron of cruisers.

Phase one: the first campaign, 1915

The first U-boat victory was spectacular and militarily useless: on 5 September 1914, U-21 sank the cruiser HMS Pathfinder with a torpedo, the first warship sunk by a submarine's self-propelled torpedo. Germany then turned to trade. On 18 February 1915 it declared the waters around the British Isles a war zone in which Allied merchant ships would be sunk on sight, with a warning that neutral ships might be hit by mistake. On 7 May a single torpedo from U-20 sank the liner Lusitania off the southern coast of Ireland. About 1,200 people died, including 128 Americans, and the outrage in the United States brought the two countries close to war. Germany, then without enough submarines to risk American entry, restricted its operations that autumn.

Phase two: the Sussex pledge, 1916

The campaign resumed in early 1916 under rules which required submarines to surface, warn the crew, and allow them to take to boats before sinking a merchant ship. After the Channel steamer Sussex was torpedoed on 24 March, with dozens of passengers killed, President Wilson threatened to break relations, and Germany gave the "Sussex pledge" on 4 May 1916: no more sinkings without warning. Tirpitz had already resigned in March in protest at the Kaiser's refusal to sanction unrestricted warfare. The pledge held until the end of January 1917.

Phase three: unrestricted warfare, 1917

After Jutland, the Verdun stalemate and a bad harvest, the German leadership decided to gamble. A memorandum by the naval staff chief Admiral Henning von Holtzendorff argued that if 600,000 tons of shipping were sunk per month, Britain would be forced to make peace in five months, before American help could arrive. On 31 January 1917 Germany announced that from the next day its submarines would sink every ship in the war zone without warning. The United States broke relations on 3 February and declared war on 6 April (see chapter VI). Meanwhile the results were everything the admirals promised. In February, German boats sank more than 500,000 tons; in March nearly 600,000; and in April about 860,000 tons, the peak of the war. One ship in four leaving British ports did not come back. By April Britain had perhaps six weeks of wheat in stock, and Jellicoe, then First Sea Lord, told the American Admiral William Sims in confidence that the country could not continue the war if losses on this scale persisted.

Phase four: the answer, 1917 to 1918

The remedy was the convoy: grouping merchant ships and shepherding them across the ocean with escorts. The Admiralty had been reluctant. It feared that large groups of ships would offer concentrated targets, believed the Royal Navy lacked escorts, and thought merchant captains could not keep station. Lloyd George later claimed credit for forcing it to change its mind, and junior officers pressed the case; historians emphasize that Jellicoe's staff was already working on a scheme. The first experimental convoy sailed from Gibraltar on 10 May 1917, and Atlantic convoys began the same month. Its results were striking: in convoy, fewer than one ship in a hundred was lost. The reason was geometrical. The ocean is wide and a U-boat can only see a few miles; a convoy of 30 ships was hardly easier to find than a single ship, so the number of encounters fell sharply while the escorts guarded the whole group. By the autumn, monthly losses had dropped to less than half the April peak, and the American entry brought destroyers, shipbuilding and a surge of cargo hulls.

The tools of the hunt

Convoys were helped by technology. Depth charges, canisters of explosive set off by a hydrostatic pistol at a preset depth, entered service in 1916 and were carried by destroyers and sloops in growing numbers. Hydrophones, underwater microphones, allowed escorts to locate a submerged boat by its engine noise. Mines, nets, airships and seaplanes patrolled the coast. "Q-ships", merchant vessels with hidden guns, lured U-boats to the surface; they sank a dozen or so submarines, but at a high price, and the notorious Baralong incident of August 1915, in which survivors of U-27 were shot, left a legacy of bitterness. After the Armistice, 176 surrendered U-boats were handed over. The campaign failed because Holtzendorff was wrong about the timetable, and because it brought the United States into the war.

If the submarines could not be stopped at sea, perhaps they could be bottled up in their harbors or trapped in the narrow passages they had to use. Much of the Allied navies' energy in 1916 to 1918 went into attempts to close such passages with barrages of mines, nets and patrol craft, and into raids on the submarine bases themselves.

The Dover Barrage

U-boats of the Flanders Flotilla, based at Bruges and its ports of Zeebrugge and Ostend, could reach the English Channel and the Western Approaches by a short passage through the Strait of Dover, which is only 21 miles across. The Dover Patrol, under Vice-Admiral Reginald Bacon, tried to seal it with lines of mines and anti-submarine nets, patrolled by trawlers and drifters. Early barrages were disappointing: the British mines were unreliable, the nets were easily slipped, and German destroyers from Flanders raided the patrol vessels in October 1916 and April 1917 (the second raid met a spirited defense by the destroyers Broke and Swift). In early 1918 Rear-Admiral Roger Keyes replaced Bacon, strengthened the barrage with better mines, a lit and patrolled deep minefield, and a more aggressive defense. Many boats, however, simply went around Scotland instead.

The Northern and Otranto Barrages

A far larger project was the North Sea Mine Barrage, a belt of mines from the Orkneys to the Norwegian coast intended to block the northern route. Pressed by the Americans, it was laid by the United States Navy and Royal Navy between June and October 1918, using about 70,000 mines, most of them American. Its military value is debated; it sank perhaps a handful of U-boats. In the Adriatic the Allies maintained the Otranto Barrage, a line of nets, drifters and patrol craft across the 45-mile Strait of Otranto, to keep the Austro-Hungarian and German boats at Pola and Cattaro from reaching the Mediterranean. On 15 May 1917 Captain Miklós Horthy, later regent of Hungary, led three light cruisers through the strait and sank 14 of the 47 drifters on patrol before the Allies could respond, and Horthy was wounded in the fight. The barrage never became airtight.

The Zeebrugge raid

The most daring answer was a raid on the base itself. Zeebrugge, on the Belgian coast, is linked to Bruges by a canal, and a long curved breakwater, the Mole, shelters the harbor. Keyes conceived an operation to block the canal mouth with sunken ships. On the night of 22 to 23 April 1918, St George's Day, an assault force of about 1,700 men in some 75 vessels sailed from Dover. The old cruiser HMS Vindictive was brought alongside the Mole under cover of an artificial smoke screen, and landing parties went ashore to attack the German batteries; an old submarine packed with explosives, C3, rammed the viaduct linking the Mole to the shore and was blown up, cutting off reinforcements; and three old cruisers, Thetis, Intrepid and Iphigenia, were driven into the canal entrance and scuttled. A similar attempt at Ostend failed that night and a second try in May succeeded only in part.

Eight Victoria Crosses were awarded for Zeebrugge, and Britain, at a low moment in the war, celebrated. The strategic result was disappointing. The blockships ended up slightly out of position, and within days a gap allowed small U-boats to pass at high tide. About 230 British sailors and marines were killed. The Flanders Flotilla's boats continued to sail until the German retreat in October 1918, when the Belgian coast was evacuated. The raid is a good illustration of the war at sea in its latter half: heroism and ingenuity in the service of a limited objective.

The story of the battle of Jutland on 31 May and 1 June 1916 belongs to chapter V. Here the question is a different one: why did a fleet that was far stronger lose more ships and more than twice as many men, and why did the Royal Navy fail to win the decisive victory the nation had expected? The answers lie in technology, training and communications, all of which Jutland tested for the first time at full scale.

The numbers were stark. The British lost 14 ships, among them three battlecruisers (Indefatigable, Queen Mary and Invincible) and three armored cruisers, and 6,094 men. The Germans lost 11 ships, including one battlecruiser, and 2,551 men. In round numbers, both sides' heavy guns hit with only a few percent of their shells: each side scored roughly 100 to 125 hits from several thousand heavy shells fired (the sources differ slightly).

Gunnery and fire control

Gunnery in 1916 was a problem of mathematics. A battleship firing at ten miles, moving at 20 knots at an enemy moving at 20 knots, had to predict where the target would be some 30 seconds later, when the shell arrived. The British solved it with the Dreyer Fire Control Table, a mechanical computer that tracked the speed and course of the enemy and one's own ship and predicted the range, and with directors, sights high in the ship from which all guns could be aimed and fired together. The Germans used stereoscopic rangefinders, which many officers believed did better in poor light, and quick, disciplined salvo drills. Their gunnery was excellent, particularly in the opening phase, when Hipper's battlecruisers found the range on Beatty's ships very quickly. British battlecruisers, which had lighter armor and less advanced fire control than the battleships, suffered most.

The exploding battlecruisers

Three British battlecruisers blew up. At 4:02 p.m. Indefatigable was hit by shells from von der Tann and exploded; at 4:26 Queen Mary, struck by Derfflinger and Seydlitz, vanished in a column of smoke and flame. It was then that Beatty is said to have remarked that there seemed to be something wrong with our bloody ships today. Invincible exploded in two at 6:33, and only six of her crew survived. The cause was the handling of propellant. British charges were bags of cordite that burned fiercely if a flash reached them; in the interest of firing rapidly, crews often stacked charges in turret working chambers and propped open the flash-tight doors, so a shell bursting inside a turret could send a flash down the ammunition hoist to the magazine. German ships kept their main charges in brass cartridge cases and used a more stable propellant, and, after a near-disaster on Seydlitz at the Dogger Bank, had improved flash protection. The British had not. After Jutland the Royal Navy changed its rules and fitted flash screens.

Signals, scouting and night fighting

Communications failed repeatedly. Wireless transmissions were cumbersome and subject to interference, so fleets relied on flag hoists and signal lamps, which were slow, vulnerable to smoke and spray, and sometimes ignored. At the start of the battle Beatty turned his battlecruisers, but the battleships of Rear-Admiral Hugh Evan-Thomas's 5th Battle Squadron did not read the flag signal quickly and kept going. Jellicoe learned the position of the German fleet late and imperfectly, because reports from scouts were infrequent, and had to deploy his 24 dreadnoughts into battle line blind. The Admiralty's own mistakes made it worse: it told Jellicoe at midday that the German commander Scheer's flagship was still in port, because the flagship's call sign had been transferred to a shore station.

The Germans fought better at night. They had superior searchlights and star-shell drills, and a doctrine for night action; the armored cruiser Black Prince, which blundered into the German line, was destroyed in minutes with all 857 men aboard. The Germans' rehearsed 180-degree "battle turn-away", executed by the whole line at once, got Scheer out of Jellicoe's trap twice. Jellicoe, wary of torpedoes and mines and unwilling to risk the fleet in a night action he could not control, kept his course south. At dawn the German fleet was home.

The verdict is mixed. Britain lost more ships and men; Germany failed to break the blockade, and the High Seas Fleet never again challenged the Grand Fleet in force. Scheer himself reported to the Kaiser in July 1916 that only the submarine could defeat Britain, which helped to lead to unrestricted warfare. The Royal Navy responded by repairing its faults: better shells, flash protection, improved night-fighting, and a more flexible signal system.

Outside the North Sea and the Atlantic, the war at sea was fought in a series of semi-enclosed seas, each of which had its own geography and logic.

The Goeben and the Dardanelles

On the eve of war the German battlecruiser Goeben and light cruiser Breslau, commanded by Rear-Admiral Wilhelm Souchon, were in the Mediterranean. Faster than the British ships that were supposed to catch them, they eluded their pursuers and reached the Dardanelles on 10 August 1914, where they were transferred nominally to the Ottoman Navy. On 29 October Souchon, still in command, led them into the Black Sea to bombard Russian ports, and the Ottoman Empire was at war (see chapter III). The British admirals who let her escape were investigated. Goeben remained a thorn in the Allied side for years: in January 1918 she sortied with Breslau against British monitors at Imbros, sank two of them, and then ran into a minefield, losing Breslau and being damaged herself.

The Allies attacked the Dardanelles in return. On 18 March 1915 an Anglo-French fleet of 18 battleships tried to force the Narrows, but a line of mines laid by the Turkish minelayer Nusret on the night of 7 to 8 March sank three battleships (HMS Irresistible, HMS Ocean and the French Bouvet, which went down in about two minutes with most of her crew) and crippled others. The attempt was abandoned, and the failure led to the landings at Gallipoli. Allied submarines such as E11 and E14 later passed the minefields and operated in the Sea of Marmara, sinking Turkish supply ships.

The Adriatic

Austria-Hungary built four modern dreadnoughts, Viribus Unitis, Tegetthoff, Prinz Eugen and Szent István, but kept them at Pola (Pula), fearing their loss. Italy, which entered the war in May 1915, similarly held back its battle fleet. The Austro-Hungarian cruisers bombarded Ancona on 24 May 1915, the day after Italy declared war; submarines such as Georg von Trapp's U-5, which sank the French armored cruiser Léon Gambetta on 27 April 1915 with 684 dead, took a steady toll; and both sides lost warships to mines and sabotage. The main contest was the Otranto Barrage. Eventually the Italians found an answer in the MAS, small, fast, motor torpedo boats, which could slip into harbors. On 10 December 1917 two MAS boats under Luigi Rizzo entered Trieste harbor and sank the old coastal defense ship Wien. And on 10 June 1918, when the Austro-Hungarian fleet sailed for a second raid on the Otranto Strait, Rizzo's MAS 15 met the squadron off the island of Premuda and sank the dreadnought Szent István with two torpedoes. The ship rolled over after about three hours; fewer than 100 of her crew died, and the event was filmed. The Austro-Hungarian Navy abandoned its raid, and never again left port in force.

The Black Sea

The Black Sea was a Russian and Ottoman lake in which Goeben, renamed Yavuz Sultan Selim, was the strongest ship. The Russian fleet had older battleships and, from 1915, the new dreadnought Imperatritsa Mariya. Russian ships mined the approaches to the Bosporus, cut off the Ottoman coal supply from the Zonguldak mines, and supported the army's capture of Trebizond in April 1916. In October 1916 a fire in a magazine destroyed Imperatritsa Mariya in the harbor at Sevastopol. Admiral Alexander Kolchak, appointed in 1916, was the Russian fleet's most capable commander. After the revolution of 1917, the fleet disintegrated.

The Baltic

In the Baltic, Germany's dominance was greatest. The Russian navy, with a few modern battleships, defended the Gulf of Finland behind minefields. A German attempt to enter the Gulf of Riga in August 1915 was beaten off, but in October 1917 Operation Albion, a combined operation by about 300 vessels (including ten battleships and a battlecruiser) and 25,000 soldiers, seized the islands of Ösel and Dagö and forced the Russians out of Moon Sound; the old battleship Slava had to be scuttled. British submarines operated in the Baltic from 1914 from Russian bases, and sank German warships and ore ships; after the Bolshevik revolution their commander Francis Cromie scuttled them off Helsinki in April 1918 to prevent their capture, and he was killed in August when the Bolsheviks stormed the British embassy in Petrograd.

In August 1914 aircraft were so new that the generals who took them to war were not sure what they were for. Britain sent 63 airplanes of the Royal Flying Corps to France with the BEF; the French and Germans each had a few hundred. They were frail machines of wood, fabric and wire, flown by officers who were often cavalrymen, and their job was reconnaissance. It was well done. On 3 September 1914, French and British airmen reported that von Kluck's German First Army was turning southeast of Paris, exposing its flank; the information helped General Gallieni launch the counterattack that became the battle of the Marne. Within months aircraft were photographing trench lines and using wireless to direct artillery. By 1918 aerial photographs and aerial observation were an essential part of every offensive.

Learning to kill in the air

Armed combat evolved quickly. The first aircraft shot down by another airplane fell on 5 October 1914, when a French Voisin with a machine gun mounted in front brought down a German Aviatik near Reims. The problem was how to fire a machine gun forward without hitting the propeller. In April 1915 the French pilot Roland Garros fitted steel deflector wedges to his propeller blades and shot down several German aircraft in a fortnight before he was captured. His plane was examined by German engineers and by the Dutch designer Anthony Fokker, whose team perfected an interrupter gear that synchronized the gun with the propeller. Fitted to the Fokker E.I monoplane, the "Eindecker", it made the German pilots Max Immelmann and Oswald Boelcke the terror of the Western Front in the "Fokker Scourge" of late 1915 and early 1916. The Allies responded with pusher aircraft such as the DH.2, with the nimble Nieuport 11, and eventually with their own synchronizing gear.

From 1916 the war in the air became organized. Boelcke helped to organize the first fighter squadrons (Jagdstaffeln) and wrote a code of tactical rules, the Dicta Boelcke: attack from the sun, attack from behind, never turn your back to the enemy. The French and British followed with the SPAD S.VII, the Sopwith Camel, the SE5a and others. Pilots flew in formations of several aircraft; the German "flying circus" of Manfred von Richthofen's Jagdgeschwader 1, painted in bright colors, flew in dozens. Machine guns, fixed to the airframe and aimed by pointing the whole plane, produced a game of speed and maneuver, in the cloud and in the sun.

The knights of the air

The press and the governments needed heroes, and in the grinding war of the trenches the fighter pilot was an irresistible one: young, alone, apparently chivalrous. The French newspapers coined the word "ace" for any pilot with five victories. Richthofen, the "Red Baron", became a national idol; Guynemer was revered in France; Albert Ball and Mannock were national heroes in Britain. Pilots on both sides did show remarkable gestures of respect: Richthofen was buried with full military honors by Australian airmen when he was killed on 21 April 1918, probably by ground fire (the credit is still disputed between Australian gunners and the Canadian pilot Roy Brown). But the legend hid a harsher truth. Most victories were scored against slow reconnaissance machines, often by surprise from behind, not by duels; the aces lived by caution as much as courage, and many were killed. The aircrews of the Royal Flying Corps were denied parachutes on the grounds that they might abandon their aircraft, while the Germans issued them in 1918. The poet W. B. Yeats captured a different mood in his poem on the death of an Irish airman: he fights neither from hatred nor from love.

Bloody April

The worst moment for the British came in the spring of 1917. During the Arras offensive, the RFC, under Hugh Trenchard's policy of aggressive patrolling over the German lines, flew obsolete machines and inexperienced pilots into the new Albatros D.III fighters of the German Jastas, which were better armed and fought on their own side of the line. In April 1917, now known as "Bloody April", the RFC lost some 245 aircraft and hundreds of aircrew, several times the German losses. Contemporary reports said that a new pilot at the front might last only a few weeks. Even worse, many pilots were barely trained; more British airmen died in training and accidents than in combat at some points in the war. The RFC recovered with better aircraft and more training, and by 1918 the Allies had air superiority in numbers.

Long before 1914, writers like H. G. Wells had imagined bombers destroying cities. In January 1915 the idea became reality. On the night of 19 to 20 January two German naval Zeppelins, L3 and L4, crossed the North Sea and dropped bombs on Great Yarmouth, King's Lynn and nearby villages, killing four people. It was the first strategic air raid in history. London was first bombed on 31 May 1915, and by the end of the war the German army and navy had flown around 50 airship raids on Britain, which killed about 557 people and injured about 1,350.

The Zeppelins were vast: a Zeppelin of 1916 was over 650 feet long, carried a crew of 20 or more and could climb to 10,000 feet, out of reach of most guns and aircraft. But they were fragile, slow, hard to navigate and filled with hydrogen. Britain answered with searchlights, anti-aircraft guns and, above all, aircraft armed with explosive and incendiary ammunition. On the night of 2 to 3 September 1916 Lieutenant William Leefe Robinson shot down the army airship SL 11 over Cuffley, north of London, in a blazing fall seen by crowds across the capital, and won the Victoria Cross. After a handful more losses the German navy's Zeppelin chief, Peter Strasser, sent his craft higher, to 20,000 feet, where crews suffered from cold and altitude, and they bombed inaccurately. The "Silent Raid" of 19 to 20 October 1917 cost the Germans several airships, lost in strong winds over France, and the last raids ended in 1918, when Strasser was killed on 5 August as his airship L70 was shot down in flames off the Norfolk coast.

The Gothas

By 1917 the Germans had turned to airplanes. The Gotha G.IV, a twin-engined biplane bomber, carried a 1,000-pound bomb load, and a special unit, Kagohl 3, was formed for the attack on England. On 25 May 1917, 21 Gothas bombed Folkestone in daylight, killing 95. On 13 June 1917, 14 Gothas reached London itself, and bombed the City and the East End in the middle of the morning. About 162 people were killed, including 18 children at a school in Upper North Street, Poplar, the deadliest raid of the war on Britain. The defenses could do little, and the public was furious. Daylight raids ended after August, but the Gothas, and later the giant four-engined "Giants" of the Zeppelin-Staaken works, came back by night. Londoners, for the first time, took shelter in the underground stations. The last major raid was on the night of 19 to 20 May 1918. Together the airplane raids killed some 850 people; with the airships, about 1,400 people died in British air raids in the war.

The Smuts report and the RAF

Smuts delivered two reports in the summer of 1917. The first reorganized London's air defenses. The second, on 17 August, went further: it argued that the Army's Royal Flying Corps and the Navy's Royal Naval Air Service, which competed for aircraft and engines, should be merged into a single service under a new Air Ministry, and it predicted that aerial operations might become the principal operations of war. Parliament passed the Air Force Act in November, and on 1 April 1918 the Royal Air Force came into being, the first independent air force in the world, with more than 20,000 aircraft and nearly 300,000 personnel by the Armistice.

The Independent Force

Trenchard became the RAF's first Chief of the Air Staff in January 1918 but resigned in a quarrel with the Air Minister; in June he was sent to command the Independent Force, based near Nancy, which was meant to attack German industry and cities in retaliation. It flew Handley Page and DH.9 bombers on raids against Cologne, Mainz, Stuttgart and other targets in western Germany, and dropped about 550 tons of bombs before the Armistice. The material damage was slight and the cost was heavy, but Trenchard became a believer in the "moral effect" of bombing, and the Independent Force's example, and Smuts's prophecy, shaped British doctrine between the wars. The Italians, too, flew Caproni bombers against Austrian towns, and on 9 August 1918 the poet Gabriele D'Annunzio led a squadron to drop leaflets on Vienna.

Naval aviation began as an extension of the fleet's eyes. The Royal Navy converted fast cross-Channel steamers into seaplane carriers: HMS Engadine, Riviera and Empress, which on Christmas Day 1914 sent seven seaplanes against the Zeppelin sheds at Cuxhaven in the first seaborne air operation by the Royal Navy (the raid did little damage). The Japanese seaplane carrier Wakamiya had already used floatplanes against German positions at Tsingtao in the autumn of 1914. At the Dardanelles in August 1915, a Short 184 seaplane from the carrier Ben-my-Chree, flown by Flight Commander Charles Edmonds, torpedoed a Turkish supply ship on 12 August, the first attack on a ship by a torpedo dropped from an aircraft (the ship had already been crippled by a British submarine); five days later Edmonds sank another vessel outright, the first ship sunk by this method alone.

At Jutland, Engadine launched a seaplane flown by Flight Lieutenant Frederick Rutland, "Rutland of Jutland", who found the German light cruisers and radioed their position, the first time an aircraft had scouted in a fleet action. The weak point of the seaplane carrier was that its aircraft had to be lowered on to the water and recovered by crane, which took time and demanded calm seas. The solution was a flight deck.

From Furious to Argus

HMS Furious was begun as a "large light cruiser" armed with two enormous 18-inch guns. Completed in 1917 with a flying-off deck built where the forward turret was meant to be, she could launch wheeled aircraft such as the Sopwith Pup. Landing was another matter. On 2 August 1917 Squadron Commander Edwin Dunning flew a Pup in from astern and landed on the forward deck while Furious steamed into the wind at some 26 knots, the first landing on a moving ship. Five days later he made a third attempt, was swept over the side, and drowned. Furious was then fitted with a second, aft deck for landing, but the turbulence from her funnel and superstructure made it very dangerous. The answer was a clear flush deck over the whole length of the ship. HMS Argus, converted from an Italian liner that was building in Britain, was completed in September 1918 and was the first aircraft carrier with a full-length flight deck, the model for all later ships. She was too late to see action.

Tondern

The first strike flown from an aircraft carrier took place before the war ended. On 19 July 1918 seven Sopwith Camels flew from Furious in the North Sea against the German Zeppelin base at Tondern, in Schleswig (one turned back with engine trouble). Carrying two 50-pound bombs each, they destroyed two Zeppelins, L54 and L60, in their sheds. The pilots had no way of landing back on Furious, so most ditched alongside the escorting destroyers or flew to neutral Denmark. The raid showed that the carrier could project air power against land targets, and it was the model for the Japanese and American carrier strikes of the next war.

The end of the fleets

Back in Germany, the navy's final act was not a battle but a mutiny. On 24 October 1918, as the army was collapsing, Admirals Scheer and Hipper ordered a last sortie by the High Seas Fleet into the North Sea, a "death ride" to save the navy's honor. On 29 October crews at Wilhelmshaven refused to sail, and on 3 November the revolt reached Kiel; within days it had spread through Germany and helped to topple the Kaiser (see chapters VII and VIII).

The armistice terms required the internment of the High Seas Fleet. On 21 November 1918 the German ships, led into the Firth of Forth by the Grand Fleet in a long, silent column, surrendered; they were then taken to Scapa Flow, where 74 ships remained for seven months under the command of Rear-Admiral Ludwig von Reuter, with skeleton crews. As the peace conference dragged on, he feared that the ships would be divided among the victors. On the morning of 21 June 1919, with the British battle squadron out on exercise, Reuter ran up a signal, "Paragraph Eleven. Confirm", and the Germans opened their sea cocks. By evening 52 of the 74 ships were on the bottom, including every battlecruiser and 10 of 11 battleships. British guard boats opened fire, killing nine German sailors. Reuter, who afterwards said that he believed the armistice would expire that day, was detained but was not punished; the scuttling was regarded in Germany as a point of honor. The wrecks were salvaged in the 1920s and 1930s, and seven remain, a famous site for divers.