On 1 July 1916, the first day of the Battle of the Somme, the British Army endured the bloodiest day in its history, suffering 57,470 casualties and 19,240 dead; nine Victoria Crosses were awarded for action on that day. Most of the casualties occurred in the first hour of the attack. The entire Somme offensive cost the British Army almost half a million men. The war was not just fought on land; the First World War saw major naval battles as well as the first large-scale use of military aircraft. The war at sea was mainly characterized by the efforts of the Allied Powers in blockading the Central Powers by sea. In return, the Central Powers attempted to break that blockade and establish an effective blockade of the British Isles and France with U-boats and raiders. The largest naval battle of the First World War was the Battle of Jutland which was the only full-scale clash of battleships in that war. Four Victoria Crosses were awarded for action at Jutland. The war in the air saw 19 VCs being awarded to airmen. The First World War saw significant interest in flying aces, including the German Manfred von Richthofen—also known as The Red Baron—as well as British aces such as Albert Ball, Mick Mannock and Billy Bishop, who were all Victoria Cross recipients. Hostilities ended on 11 November 1918 with the signing of the Armistice Treaty in the Compiègne Forest, but the war was not officially over until the various peace treaties were signed in 1919. By the war's end, four major imperial powers – Germany, Russia, Austria-Hungary, and the Ottoman Empire—had been militarily and politically defeated, and the latter two ceased to exist as autonomous entities. Of the 60 million European soldiers who were mobilized from 1914–1918, 8 million were killed, 7 million were permanently disabled, and 15 million were seriously injured.