Battle of Wakefield
According to Shakespeare's, "Henry VI, Part 3" following Hall's Chronicle and Holinshed's Chronicles, it was Thomas Clifford's son and heir, John Clifford, 9th Baron de Clifford, who slew, in cold blood after the Battle of Wakefield, the young Edmund, Earl of Rutland, son of Richard, 3rd Duke of York, cutting off his head and sending it crowned with paper to Henry VI's wife, Margaret of Anjou, although later authorities state that Lord Rutland had been slain during the battle.