PORTLAND, WILLIAM BENTINCK, EARL OF (c. 1645-1709), English statesman, was born, according to the Dutch historian, Groen van Prinsterer, in 1645, although most of the other authorities give the date as 1649. The son of Henry Ben tinck of Diepenheim, he was descended from an ancient and noble family of Gelderland. As page of honour and gentleman of the bedchamber to William, prince of Orange, he secured the friendship of William ; which he justified by his prudence and ability. In 1677 he was sent to England to solicit for the prince of Orange, the hand of Mary, daughter of James duke of York, afterwards James II., and he was again in England in 1683 and in 1685. When, in 1688, William was preparing for his invasion Bentinck went to some of the German princes to secure their support, or at least their neutrality, and he was also a medium of communication between his master and his English friends. He superintended the arrangements for the expedition and sailed to England with the prince.
The revolution accomplished, Bentinck was made groom of the stole, first gentleman of the bedchamber, and a privy councillor; and in April 1689 he was created Baron Cirencester, Viscount Woodstock and earl of Portland. He fought at the battle of the Boyne (1690), the battle of Landen, and at the siege of Namur, but his main work was of a diplomatic nature. He helped to arrange the peace of Ryswick (1697) ; he negotiated with Louis XIV. for a partition of the Spanish monarchy, and as William's
representative, signed the two partition treaties. Jealous of the rising influence of Arnold van Keppel, earl of Albemarle, Portland resigned all his offices in the royal household in 1692, but he did not forfeit the esteem of the king, who continued to trust and employ him. He received 135,000 ac. of land in Ireland, and only the strong opposition of a united House of Commons prevented him obtaining a large gift of crown lands in North Wales. For his share in drawing up the partition treaties he was impeached in 1701, but the case against him was not proceeded with. He was occasionally employed on public business under Anne until his death at his residence, Bulstrode in Buckinghamshire, on Nov. 23, 1709. Portland's eldest son Henry (168o-1724) succeeded as 2nd earl. He was created marquess of Titchfield and duke of Portland in See G. Burnet, History of My Own Time (Oxford, 1833) ; Lord Macaulay, History of England ; L. von Ranke, Englische Geschichte (Eng. trans., Oxford, 1875) ; and especially Onno Klopp, Der Fall des Hauses Stuart (Vienna, 1875-88) ; M. E. Grew, William Bentinck and William III. (1924). See also Dr. A. W. Ward's article in vol. iv. of the Dict. Nat. Biog.