Henry Holland, 3rd Duke of Exeter (27 June 1430 – September 1475) was a Lancastrian leader during the English Wars of the Roses. He was the only son of John Holland, 2nd Duke of Exeter, and his first wife Lady Anne Stafford. His maternal grandparents were Edmund Stafford, 5th Earl of Stafford, and Anne of Gloucester.
Exeter was for a time Constable of the Tower of London.
He was a commander at the Lancastrian defeat at the Battle of Towton. He fled to Scotland after the battle, and then joined Queen Margaret in her exile in France. He was attainted in 1461, and his estates were given to his wife, who separated from him in 1464. During the brief period of Henry VI's restoration he was able to regain many of his estates and posts.
At the Battle of Barnet, Exeter commanded the Lancastrian left flank. He was badly wounded and left for dead, but survived. Afterwards he was imprisoned, and Anne divorced him in 1472. He "volunteered" to serve on Edward IV's 1475 expedition to France. On the return voyage he fell overboard and drowned. Some say he was in fact thrown overboard at the king's command.
More information on the Wikipedia page