Edward George Geoffrey Smith-Stanley, 14th Earl of Derby, KG, PC (29 March 1799–23 October 1869) was an English statesman. He served as Prime Minister of the United Kingdom three times. To date, Derby was the longest serving leader of the Conservative Party. Derby is one of only four British Prime Ministers to have been in office three or more times. However each time he was only in office for less than two years. Derby was Prime Minister for a total of just over four years, less than many other Prime Ministers.