DORCHESTER, DUDLEY CARLETON, VISCOUNT (1573-1632), English diplomatist, son of Antony Carleton of Baldwin Brightwell, Oxfordshire, was born on March 1o, 1573, and educated at Westminster school and Christ Church, Oxford, where he graduated M.A. in 1600. As secretary to the earl of Northum berland his name was associated with the Gunpowder Plot, but he succeeded in clearing himself. In 1610 he was knighted and was sent as ambassador to Venice, where he concluded the Treaty of Asti. In 1616 he was appointed ambassador to Holland. In his house at The Hague the unfortunate Elector Frederick and the princess Elizabeth took refuge in 1621. Carleton returned to England in 1625 with the duke of Buckingham, and was made vice-chamberlain of the household and a privy councillor. After an abortive mission to France he returned in 1626 and sought in the House of Commons (he had been a member since 1604) to defend his patron, the duke of Buckingham. Created Baron Carle ton of Imbercourt, and, after another mission to The Hague, Vis count Dorchester (1628), he supported the conferences between Buckingham and Contarini for a peace with France on the eve of the duke's intended departure for La Rochelle, which was pre vented by Buckingham's assassination. In December 1628 he was made principal secretary of State, and died on Feb. 15, 163 2. His voluminous correspondence, remarkable for its clear, easy and effective style and for the writer's grasp of the main points of policy, covers practically the whole history of foreign affairs during the period 1610-1628, and furnishes valuable material for the study of the Thirty Years' War. His letters as ambassador at The Hague, Jan. 1616 to Dec. 162o, were first edited by Philip Yorke, afterwards second earl of Hardwicke, with a biographical and historical preface, in 1757; his correspondence from The Hague in 1627 by Sir Thomas Phillipps in 1841 ; other letters are printed in the Cabala and in T. Birch's Court and Times of James I. and Charles I., but by far the greater portion remains in ms. among the State papers.