As a key figure of the Restoration administration, William Bruce became close to other Stuart loyalists, who included such powerful patrons as the Duke of Lauderdale, Lord Haltoun, and the Earl of Rothes. In 1668 he was created a Baronet of Nova Scotia. From 1669 to 1674 Bruce sat in the Scottish Parliament as shire commissioner for Fife, and from 1681 to 1682 as a shire commissioner for Kinross.[13] From April 1685 to May 1686 he reached the peak of his political career, as a member of the Privy Council of Scotland. In 1674 he came into conflict with his patron Lord Lauderlade (and especially with the Duchess) for whom he was redoing Ham House, which resulted in his loosing his royal commissions. As an episcopalian he was mistrusted by the regime of James II and fell completely out of favour after the Glorious Revolution. As a Jacobite, in 1693 he was briefly imprisoned in Stirling Castle for refusing to appear before the Privy Council. He was incarcerated again at Stirling in 1694, and from 1696 in Edinburgh Castle. Bruce was expelled from parliament in 1702, his seat passing to his son John Bruce. Despite these imprisonments, he continued his architectural work, indeed the 1690s and 1700s were his most prolific years. Bruce was imprisoned at Edinburgh Castle again in 1708 and was only released a short time before his death, at the beginning of 1710.