William Thomas Spencer Wentworth-FitzWilliam, 6th Earl FitzWilliam (12 October 1815 – 20 February 1902), styled Hon.

One of England's richest man when he died, he left a colossal sum of £3 billion (in 2008 money) making his fortune from Yorkshire coal.

[3] Two years earlier, his elder brother had died without male issue, and he became heir to his father's estates and took the courtesy title Viscount Milton.

[3] Promoted Major for the 3rd battalion Oxfordshire and Buckinghamshire Light Infantry, he also held a number of other military posts.

[3] As his eldest son predeceased him, his titles passed to his grandson, William Wentworth-Fitzwilliam, 7th Earl of Fitzwilliam.