Sir Hiram Stevens Maxim (5 February 1840 – 24 November 1916) was an inventor who moved from the United States to the United Kingdom at the age of 41. He remained an American citizen until he became a naturalised British subject in 1900. He was the inventor of the Maxim Gun – the first portable, fully automatic machine gun – and held patents on mechanical devices such as a mousetrap, hair-curling irons, and steam pumps.