Robert Devereux, 2nd Earl of Essex (10 November 1566 – 25 February 1601), favourite of Queen Elizabeth I of England, is the best-known of the many holders of the title "Earl of Essex".
He was born at Netherwood in 1566, the son of Walter Devereux, 1st Earl of Essex and Lettice Knollys. Robert Devereux was brought up largely on his father's estate in Wales, and was educated at Cambridge. Walter Devereux died in 1576. Four years later, in 1580, Lettice married Robert Dudley, Earl of Leicester, long-standing favourite of the queen. Essex did military service under his stepfather before himself making an impact at court and winning the queen's favour. In 1590, he married Frances Walsingham, daughter of Sir Francis Walsingham. Frances was also the widow of Sir Philip Sidney – who had died at the Battle of Zutphen, in which Essex had distinguished himself. And futhermore, Sir Philip Sidney was the nephew of Robert Dudley (d 1588) who had been Robert's stepfather for eight years.
Essex's star was in the ascendant. In 1591, he was given command of a force sent to the assistance of the Protestant King Henry IV of France. In 1596, he distinguished himself once again, by the capture of Cádiz. In the meantime, he had effectively become the queen's foreign secretary and favourite, especially in the period after Leicester's death in 1588. However, he overreached himself when he attempted an expedition to the Azores, and failed again as Lord Lieutenant of Ireland, a post which Elizabeth had forced on him because she felt he was becoming too haughty.
Having permanently fallen out with the queen, Essex unwisely attempted a political coup, raising a rebellion and attempting to seize control of the city of London on February 8, 1601.