Leicester, Robert Dudley, Earl of Leicester (c. 1532–1588)

English courtier. Son of the Duke of Northumberland, he was created Earl of Leicester in 1564. He led the disastrous military expedition (1585–87) sent to help the Netherlands against Spain. Despite this failure, he retained the favour of Queen Elizabeth I, who gave him command of the army prepared to resist the threat of Spanish invasion in 1588.

His father was executed in 1553 for supporting Lady Jane Grey's claim to the throne, and Leicester was himself briefly imprisoned in the Tower of London. His good looks attracted Queen Elizabeth, who made him Master of the Horse in 1558 and a privy councillor in 1559. He was a supporter of the Protestant cause.

Elizabeth might have married him if he had not been already married to Amy Robsart. When his wife died in 1560 after a fall downstairs, Leicester was suspected of murdering her. In 1578 he secretly married the widow of the Earl of Essex.