DUDLEY, SIR ROBERT (1573-1649), titular duke of Northumberland and earl of Warwick, English explorer, engineer and author, was the son of Robert Dudley, earl of Leicester (q.v.), the favourite of Queen Elizabeth. His mother was Lady Doug las Sheffield, daughter of Thomas, first Baron Howard of Effing ham. Leicester, who deserted Lady Douglas Sheffield for Lettice Knollys, widow of the first earl of Essex, denied that they were married. Her son Robert was born in May 1573, was recognized by Leicester, and sent to Christ Church, Oxford, in 1587. He in herited all Leicester's property under the earl's will at his death in 1588, and in the following year the property of Ambrose Dudley, earl of Warwick. In 1594 he made a voyage to the West Indies, and in 1596 he took part in the expedition to Cadiz and was knighted. After the death of Elizabeth he endeavoured to secure recognition of his legitimacy, and of his right to inherit the titles of his father and uncle. The proceedings were quashed by the Star Chamber. In 1605 he obtained leave to travel abroad, and went to Italy accompanied by the beautiful Miss Elizabeth Southwell, daughter of Sir Robert Southwell of Woodrising, in the dress of a page. When ordered to return home and to provide for his de serted wife and family, he refused, was outlawed, and his prop erty was confiscated. On the continent he avowed himself a Roman Catholic, married Elizabeth Southwell at Lyons, and en tered the service of Cosimo II., grand duke of Tuscany. He was employed in draining the marshes behind Leghorn, and in the construction of the port. In Italy Dudley was known as Duca di Nortombria and Conte di Warwick. He died near Florence on Sept. 6, 1649. His deserted wife, Alicia, was created duchess of Dudley by Charles I. in 1644, and died in 167o, when the title became extinct. Dudley's chief claim to remembrance is the magnificent Arcano dell mare (Florence, 3 vols. 1645-1646, re printed 2 vols. 1661), a collection of all the naval knowledge of the age, remarkable for a scheme for the construction of a navy in five rates which Dudley designed and described.
See G. L. Craik, Romance of the Peerage (London, 1848-1850), vol. iii.; Sir N. H. Nicolas, Report of Proceedings on the Claim to the Barony of L'Isle (London, 1829) • and The Italian Biography of Sir R. Dudley, by Doctor Vaughan Thomas.