Sidney, ALGERNON (? 1622-83), son of Robert, 2nd Earl of Leicester, was probably born at Penshurst, near Tunbridge. After taking part in the suppression of the Irish rebellion (1642), he entered the Parliamentary army, and was badly wounded at Marston Moor. In 1646 he accompanied his brother, Lord Lisle, to Ireland as Lieutenant-General of the Horse, and in 1647 he was made Governor of Dover. He took no part in the trial and condemnation of Charles I., but he subsequently pronounced his execution a patriotic measure. After the dissolution of the Long Parliament (1653), he withdrew to Penshurst, and there wrote his Discourses on Government, a work advocating republican principles. He was engaged in diplomatic business at Stockholm when the Restoration occurred, and continued to reside on the Continent till 1677, when he obtained permission to return. His negotiations with the French ambassador, Barillon, from whom he is said to have received money in 1680, have given rise to much conjecture. After the death of Shaftesbury (1682) he became one of the most active leaders of the Whig party. There is no evidence that he was implicated in the Rye House Plot; nevertheless, he was brought to trial, condemned to death on the testimony of a single perjured witness, and beheaded on Tower Hill. His attainder was reversed in 1689.