Derby, Earl of
English title

It was conferred in 1485 by Henry VII of England on Thomas, second Lord Stanley, two months after the Battle of Bosworth, where he had contributed to the victory of Richmond (later Henry VII) by withdrawing his promised support for Richard III. The Stanleys were descended from Adam de Aldithley, who came with William the Conqueror to England in 1066. His grandson married the heiress of Thomas Stanley, of Stafford, and exchanged the manor of Thalk, Staffordshire, his wife's marriage portion, for Stoneley, Derbyshire, and assumed the surname of Stanley. A descendant, Sir John Stanley, who had married the heiress of Lathom, got a grant of the Isle of Man (1405), which he and his descendants ruled until 1736.