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 19 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.