Leeds, Thomas Osborne, 1st Duke of Leeds (1632–1712)

English politician who served as lord treasurer and chief minister to Charles II 1673–79, and increased the king's revenues. As a strong supporter of an independent Church of England, he opposed the pro-Catholic policies of Charles and his successor James II, and was instrumental in arranging the marriage between James's daughter Mary of York to the Protestant William of Orange in 1677. He then helped arrange for William to assume the English crown in 1688 (see Glorious Revolution). For his services, he was made duke of Leeds in 1694.

Leeds became MP for York in 1665. As Charles II's representative, he conducted secret financial dealings with Louis XIV of France, but also intrigued with the Dutch to form an alliance against France in the event of war. He was stripped of office in 1679 on charges of corruption and briefly imprisoned in the Tower in 1684. He acted as a chief adviser to William 1690–95, and regained his post as lord treasurer. Further charges of bribery were made against him, and his power gradually declined.