The Battle of Amiens, also known as the Third Battle of Picardy was the opening phase of the Allied offensive which began on 8 August 1918, later known as the Hundred Days Offensive, which ultimately led to the end of World War I. Allied forces advanced over on the first day, one of the greatest advances of the war, with Gen Henry Rawlinson's British Fourth Army, with nine of its 19 divisions supplied by the fast-moving Australian Corps of Lt General John Monash and Canadian Corps of Lt General Arthur Currie, and Gen Marie Eugène Debeney's French First Army playing a decisive role. The battle is also notable for its effects on both sides' morale and the large number of surrendering German forces. This led Erich Ludendorff to later describe the first day of the battle as "the black day of the German Army". Amiens was one of the first major battles involving armoured warfare.

Background

On 21 March 1918, the German Army had launched Operation Michael, the first in a series of attacks planned to drive the Allies back along the length of the Western Front. After the signing of the Treaty of Brest-Litovsk with revolutionary-controlled Russia, the Germans were able to transfer hundreds of thousands of men to the Western Front, giving them a significant, if temporary, advantage in manpower and materiel. These offensives were intended to translate this advantage into victory. Operation Michael was intended to defeat the right wing of the British Expeditionary Force (BEF), but a lack of success around Arras ensured the ultimate failure of the offensive. A final effort was aimed at the town of Amiens, a vital railway junction, but the advance had been halted at Villers-Bretonneux by British and Australian troops on 4 April.

Subsequent German offensivesOperation Georgette (9–11 April), Operation Blücher-Yorck (27 May), Operation Gneisenau (9 June) and Operation Marne-Rheims (15–17 July) all made advances elsewhere on the Western Front, but failed to achieve a decisive breakthrough.

By the end of the Marne-Rheims offensive, the German manpower advantage had been spent, and their supplies and troops were exhausted. The Allied general, General Ferdinand Foch, ordered a counteroffensive which led to victory at the Second Battle of the Marne, following which he was promoted to Marshal of France. The Germans, recognising their untenable position, withdrew from the Marne to the north. Foch now tried to move the Allies back onto the offensive.

Prelude

Plan

Foch disclosed the plan on 23 July, following the Allied victory at the Battle of Soissons. The plan called for reducing the Saint-Mihiel salient (which would later see combat in the Battle of Saint-Mihiel) and freeing the railway lines that ran through Amiens from German shellfire.

The commander of the British Expeditionary Force, Field Marshal Sir Douglas Haig, already had plans in place for an attack near Amiens. When the British retreat had ended in April, the headquarters of the British Fourth Army under General Sir Henry Rawlinson had taken over the front astride the Somme. Its left-hand corps was the British III Corps under Lieutenant General Richard Butler. At the same time, the Australian Corps under Lieutenant General John Monash held the right flank and linked up with French armies to the south. On 30 May, all the Australian infantry divisions were united under the corps HQ for the first time on the Western Front. The Australians had mounted several local counter-attacks which both revealed the suitability of the open and firm terrain south of the Somme for a larger offensive, and established and refined the methods which were to be used.

The plan's mastermind was Monash, who used the same innovation and mastery of modern technology, particularly tanks, that he had demonstrated five weeks earlier in the Battle of Hamel.

Rawlinson submitted Monash's proposals to Haig in July, and Haig forwarded them to Foch. At a meeting on 24 July, Foch agreed to the plan but insisted that the French First Army, which held the front to the south of the British Fourth Army, should participate. Rawlinson opposed this as his and Monash's plans depended on the large-scale use of tanks (now finally available in large numbers) to achieve surprise by avoiding a preliminary bombardment. The French First Army lacked tanks and would be forced to bombard the German positions before the infantry advance began, thus removing the element of surprise. Eventually, it was agreed that the French would participate but not launch their attack until 45 minutes after the Fourth Army.

Battle

First phase

thumb|Map depicting the advance of the Allied line

The battle began in dense fog at 4:20 am on 8 August. Under Rawlinson's Fourth Army, the British III Corps attacked north of the Somme, the Australian Corps to the south of the river in the centre of Fourth Army's front, and the Canadian Corps to the south of the Australians. The French 1st Army under General Debeney opened its preliminary bombardment at the same time and began its advance 45 minutes later, supported by a battalion of 72 Whippet tanks. The British, Australian and Canadian infantry of the Fourth Army sustained about 8,000 casualties, with further losses by tank and air personnel, and French forces.

German Army Chief of Staff Paul von Hindenburg noted the Allies' use of surprise and that Allied destruction of German lines of communication had hampered potential German counter-attacks by isolating command positions. The German General Erich Ludendorff described the first day of Amiens as the "Schwarzer Tag des deutschen Heeres" (the "black day of the German Army"), not because of the ground lost to the advancing Allies, but because the morale of the German troops had sunk to the point where large numbers of troops began to capitulate. and the initial force of more than 500 tanks that played a prominent role in the Allied success was reduced to six battle-ready tanks within four days. On the Canadian front, congested roads and communication problems prevented the British 32nd Division from being pushed forward rapidly enough to maintain the momentum of the advance.

The Chipilly Spur was still in German hands. The Germans on the ridge commanded a wide field of fire to the south of the Somme. They poured devastating machine gun and artillery fire that kept the Australian Corps pinned down across the river at Hamel. The job of taking Chipilly Ridge was ultimately assigned to three battalions of American doughboys from the 33rd U.S. Infantry Division. According to B.J. Omanson,

During the 33rd U.S. Division's assault on Chipilly Ridge, Corporal Jake Allex, a Serbian immigrant from Kosovo, took command of his platoon after all the other officers had been killed. Corporal Allex led them in an attack against a German machine gun nest, during which he personally killed five enemy soldiers and captured fifteen prisoners. For his actions at Chipilly Ridge, Corporal Allex became the second American soldier to be awarded the Medal of Honor during the First World War.

On 10 August, there were signs that the Germans were pulling out of the salient from Operation Michael. According to official reports, the Allies had captured nearly 50,000 prisoners and 500 guns by 27 August. Even with the lessened armour, the British drove into German positions by 13 August.

Field Marshal Haig refused the request of Marshal Foch to continue the offensive, preferring instead to launch a fresh offensive by Julian Byng's Third Army between the Ancre and Scarpe. This offensive, the Second Battle of the Somme, took place 21 August – 3 September 1918.

Aftermath

thumb|280px|A German [[7.7 cm FK 96 n.A. field gun captured during the course of the battle by the 33rd Australian Battalion]]

The Battle of Amiens was a significant turning point in the tempo of the war. The Germans had started the war with the Schlieffen Plan before the Race to the Sea slowed movement on the Western Front, and the war devolved into trench warfare. The German spring offensive earlier in 1918 had once again given Germany the offensive edge on the Western Front. Armoured support helped the Allies tear a hole through trench lines, weakening once-impregnable trench positions: the British Third Army, with no armoured support, had almost no effect on the line, while the Fourth, with fewer than a thousand tanks, broke deep into German territory.