Henry Percy, known as 'Hotspur', was the impulsive son of the Earl of Northumberland. With his father, he had helped to gain the throne for Henry IV in 1399, but he soon became resentful at the behaviour of this new king, and in 1403 he joined with his uncle, Thomas Percy, Earl of Worcester, in a rebellion. They formed an alliance with Owain Glyndwr, the Welsh independence fighter and self-styled Prince of Wales. However, Henry Hotspur was killed before the two forces even got the chance to combine, in the Battle of Shrewsbury. Henry IV was said to have wept at the sight of his dead body, as the young man had been a friend of his son's, and a favourite of the king's.