Robert Devereux Essex, 2d earl of , 1567-1601, English courtier and favorite of Queen Elizabeth I . Succeeding to the earldom on the death (1576) of his father, he came under the guardianship of Lord Burghley and soon won favor at court. He distinguished himself in action while serving (1585-86) as a cavalry officer in the Netherlands under his stepfather, Robert Dudley, earl of Leicester. When he returned to England he soon became a marked favorite of the queen, a position that involved him in a quarrelsome rivalry with Sir Walter Raleigh . In 1590 he angered the queen by secretly marrying the widow of Sir Philip Sidney . The following year he commanded a flamboyant but unsuccessful expedition to Normandy to help Henry of Navarre (Henry IV of France). He returned home and, advised by Francis Bacon , entered politics in an effort to seize power from the aging Burghley. But Essex was too obvious and impetuous in his demands on the queen; Elizabeth was wary, and gradually she conferred the power he sought on Burghley's son, Robert Cecil (later earl of Salisbury ). Essex became a national hero when he shared command of the expedition that captured Cádiz in 1596, but he failed the next year in an expedition to intercept the Spanish treasure fleet off the Azores. In 1599, at his own demand, he was made lord lieutenant of Ireland and sent there with a large force to quell the rebellion of the earl of Tyrone . Failing completely to accomplish his mission, he made an...