Field Marshal Herbert Charles Onslow Plumer, 1st Viscount Plumer, (13 March 1857 – 16 July 1932) was a senior British Army officer of the First World War. After commanding V Corps at the Second Battle of Ypres in April 1915, he took command of the Second Army in May 1915 and in June 1917 won an overwhelming victory over the German Army at the Battle of Messines, which started with the simultaneous explosion of a series of mines placed by the Royal Engineers' tunnelling companies beneath German lines, which created large craters and was described as the loudest explosion in human history. He later served as Commander-in-Chief of the British Army of the Rhine and then as Governor of Malta before becoming High Commissioner of the British Mandate for Palestine in 1925 and retiring in 1928. Military career Born the son of Hall Plumer and Louisa Alice Plumer (née Turnley) and educated at Eton College and the Royal Military College, Sandhurst, Plumer was commissioned as a lieutenant into the 65th Regiment of Foot on 11 September 1876. He joined his regiment in India and became adjutant of his battalion on 29 April 1879. Promoted to captain on 29 May 1882, he accompanied his battalion to the Sudan in 1884 as part of the Nile Expedition. Plumer was present at the battle of El Teb in February 1884 and the battle of Tamai in March 1884, and was mentioned in Despatches. He spent from 1886 to 1887 attending the Staff College, Camberley, before being appointed Deputy-Assistant Adjutant-General in Jersey on 7 May 1890. He was promoted to major on 22 January 1893 and posted to the 2nd Battalion the York and Lancaster Regiment before being appointed assistant military secretary to the General Officer Commanding Cape Colony in December 1895. He went to Southern Rhodesia in 1896 to disarm the local police force following the Jameson Raid and then later that year returned there to command the Matabele Relief Force during the Second Matabele War. He became deputy assistant adjutant-general at Aldershot with promotion to brevet lieutenant colonel on 8 May 1897. In 1899 Plumer returned to Southern Rhodesia where he raised a force of mounted infantry and, having been promoted to the substantive rank of lieutenant-colonel on 17 October 1900, he led them at the Relief of Mafeking during the Second Boer War. He was promoted to colonel on 29 November