Sir Benjamin Thompson, Count Rumford, FRS (; March 26, 1753 – August 21, 1814) was an American-born British physicist and inventor whose challenges to established physical theory were part of the 19th century revolution in thermodynamics. He also served as a Lieutenant-Colonel in the Loyalist forces in America during the American Revolutionary War. After the end of the war he moved to London where his administrative talents were recognized when he was appointed a full Colonel, and in 1784 received a knighthood from King George III. A prolific designer, he also drew designs for warships. He later moved to Bavaria and entered government service there, being appointed Bavarian Army Minister and re-organizing the army, and, in 1791, was made a Count of the Holy Roman Empire.