English Protestant member of the predominantly Roman Catholic Percy family, who nevertheless died in their cause.

Brother of the 7th earl, Henry Percy served both Mary I and Elizabeth I in several capacities. During the northern rebellion, in which his brother was a leading agent, he was on the royal side, vigorously attacking the rebels. After his brother's execution in 1572, Elizabeth permitted him to assume the title of earl of Northumberland.

Nevertheless, family persuasions eventually overcame his loyalty, and he began intriguing for the escape of Mary, Queen of Scots, from imprisonment. Under suspicion, he was seized and lodged in the Tower of London for 18 months (1571–73), then released and gradually returned to favour. He was associated with the conspiracies of Francis Throckmorton (Throckmorton, Francis) (q.v.) and other Catholic agents and again sent to the Tower (September 1582), to be released after a few weeks. New intrigues brought him to the Tower a third time (December 1584), where six months later he was found dead, shot through the heart. The official verdict, probably accurate, was suicide.