(Passendale, Belgium) In 1917 the Germans began unrestricted submarine warfare, Russia crumbled under the impact of revolution and withdrew from the First World War, and part of the French army mutinied following the failure of General Nivelle's spring offensive. To relieve the resulting German pressure on the Allied forces, British Commander in Chief General Sir Douglas Haig launched an attack from the British front, which proved the most controversial of the entire war. After the British and Australian/New Zealand troops had fought weeks of grinding battle resulting in many casualties, on October 26 Lieutenant-Gen Sir Arthur Currie's Canadian Corps attacked over terrain that resembled a quagmire. By November 7, having endured appalling conditions and having suffered over 15 000 dead and wounded, the Canadians seized Passchendaele and with it 5 km2 of mud. Haig has been severely criticized for prolonging his attack, but the Canadians displayed high standards of leadership, staff work and training, and succeeded where all others had failed. Nine Victoria Crosses were awarded to Canadians after the battle.