Field Marshal Bernard Law Montgomery, 1st Viscount Montgomery of Alamein (; 17 November 1887 – 24 March 1976), nicknamed "Monty", was a senior British Army officer who served in the First World War, the Irish War of Independence and the Second World War.

Montgomery first saw action in the First World War as a junior officer of the Royal Warwickshire Regiment. At Méteren, near the Belgian border at Bailleul, he was shot through the right lung by a sniper, during the First Battle of Ypres. On returning to the Western Front as a general staff officer, he took part in the Battle of Arras in April–May 1917. He also took part in the Battle of Passchendaele in late 1917 before finishing the war as chief of staff of the 47th (2nd London) Division. In the inter-war years he commanded the 17th (Service) Battalion, Royal Fusiliers and, later, the 1st Battalion, Royal Warwickshire Regiment before becoming commander of the 9th Infantry Brigade and then general officer commanding (GOC), 8th Infantry Division.

During the Western Desert campaign of the Second World War, Montgomery commanded the British Eighth Army from August 1942. He subsequently commanded the British Eighth Army during the Allied invasion of Sicily and the Allied invasion of Italy and was in command of all Allied ground forces during the Battle of Normandy (Operation Overlord), from D-Day on 6 June 1944 until 1 September 1944. He then continued in command of the 21st Army Group for the rest of the North West Europe campaign, including the failed attempt to cross the Rhine during Operation Market Garden. When German armoured forces broke through the US lines in Belgium during the Battle of the Bulge, Montgomery received command of the northern shoulder of the Bulge.