Since Edward IV had regained the throne in 1471, Henry Tudor had lived in exile at the court of Francis II, Duke of Brittany. Henry was half-guest half-prisoner, since Francis regarded Henry, his family, and his courtiers as valuable bargaining tools to barter for the aid of England, particularly in conflicts with France, and therefore shielded the exiled Lancastrians well, repeatedly refusing to surrender them. Francis provided Henry with 40,000 gold crowns, 15,000 troops, and a fleet of ships to invade England. However, Henry's forces were scattered by a storm, compelling Henry to abandon the invasion. Nevertheless, Buckingham had already launched a revolt against Richard on 18 October 1483 with the aim of installing Henry as king. Buckingham raised a substantial number of troops from his Welsh estates, and planned to join his brother the Earl of Devon. However, without Henry's troops, Richard easily defeated Buckingham's rebellion, and the defeated duke was captured, convicted of treason, and executed in Salisbury on 2 November 1483.