Just for the hell of it I googled the name to see if anyone important ever had it. First result:
John Harrison (24 March 1693 – 24 March 1776) was a self-educated English carpenter and later a clockmaker. He invented the marine chronometer, a long-sought device in solving the problem of establishing the East-West position or longitude of a ship at sea, thus revolutionising and extending the possibility of safe long distance sea travel in the Age of Sail. The problem was considered so intractable that the British Parliament offered a prize of £20,000 (comparable to £2.87 million in modern currency) for the solution.
Harrison came 39th in the BBC's 2002 public poll of the 100 Greatest Britons.