Battle of Arras, British offensive carried out from April 9 to May 17, 1917, against the German defenses around the French city of Arras during World War I. It was noteworthy for the swift and spectacular gains made by the British in the opening phase—above all, the capture of Vimy Ridge, considered virtually impregnable, by the Canadian Corps—but it ended as a costly stalemate resulting in some 300,000 casualties.

　　The British attack in Arras opened the Allied offensive in 1917, a month after the opposing German forces had withdrawn from their more extensive positions to the shorter Hindenburg Line, forced to do so because of heavy losses that prevented them from holding their previous larger territory. The Canadian Corps was charged with taking Vimy Ridge in order to safeguard the left flank of the main advance either side of the Arras, which was entrusted to General Sir Edmund Allenby’s Third Army. The German position was well defended, but the British had planned the offensive with care, profiting from the lessons of the Somme. Artillery support was increased to nearly 3,000 guns, a substantial proportion of which were heavy cannons, essential for destroying well-constructed strongpoints.

　　Britannica Quiz World War I Quiz The British had trained their troops thoroughly in appropriate opening attack maneuvers. On 9 April, the British troops launched their assault and made good progress. The four divisions of the Canadian Corps, however, struggled up Vimy Ridge, a honeycomb of defenses that had frustrated previous French attacks with great bloodshed, provoking mutinies among numerous French units. Even after enduring a week-long artillery barrage to soften the line, the German defenders held their positions on the high ground. After a bitter fight that cost them nearly 10,000 men, the Canadians won control of the position. Farther south, the British were able to advance at several points along the front to a depth of 3 miles (4.8 km) on the first day. Two days later, however, a strong German counterattack yielded high losses among the British troops, including 3,000 Australians. On May 3, in the second phase of the battle, more than 7,000 British troops were killed, among the heaviest single-day losses of the entire war.

　　The German command avoided an Allied breakthrough with its usual adroit handling of reserves, and the British advance then lost momentum, finally grinding to a halt five weeks after the Arras offensive began. The original British plan had been to limit the battle once serious resistance was met, but British Field Marshall Douglas Haig prolonged the offensive to provide aid to the French, incurring heavy casualties for little gain.

　　The Vimy Memorial, located atop the ridge, is a major commemorative site honoring the 60,000 Canadians who died in World War I, including 13,000 who fell during the Hundred Days Offensive, which began with the Battle of Amiens, followed by the Battle of Arras.

　　Losses: British, 158,000 casualties; German, 130,000 casualties.

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