During the reign of King William however, he enjoyed some considerable posts, and was generally pretty well in his favour, and confidence.  April 21, 1702, he was sworn Lord Privy Seal, and the same year appointed one of the commissioners to treat of an union between England and Scotland, and was made Lord Lieutenant, and Custos Rotulorum for the North Riding of Yorkshire, and one of the governors of the Charterhouse.

March 9, 1703, he was created duke of Normanby, having been made marquis of Normanby by King William, and on the 19th of the same month duke of Buckingham.  In 1711 he was made Steward of her Majesty’s Houshold, and President of the Council; and on her decease, was one of the Lords Justices in Great Britain, ’till King George arrived from Hanover.

In 1710 the Whig ministry began to lose ground, and Mr. Harley, since earl of Oxford, and the Lord Treasurer made the proper use of those circumstances, yet wanting some assistance, applied to the duke of Buckingham.  The duke, who was not then on good terms with Mr. Harley, at first slighted his proposal, but afterwards joined with him and others, which produced a revolution in the ministry, and shook the power of the duke and duchess of Marlborough, while Mr. Harley, the earl of Shrewsbury, lord Bolingbroke, &c. came into the administration.  The duke was attached to Tory principles.  Her Majesty offered to make him chancellor, which he thought proper to refuse.  He was out of employment for some time, during which, he did not so much as pay his compliments at court, ’till he married his third wife, and then went to kiss her Majesty’s hand.

The duke of Buckingham, though reckoned haughty, and ill natured, was yet of a tender, compassionate disposition; but as the best characters have generally some allay, he is allowed to have been very passionate; but after his warmth subsided, he endeavoured to atone for it by acts of kindness and beneficence to those upon whom his passion had vented itself.  Several years before his grace died, he was well known to have expressed some concern for the libertinism of his youth, especially regarding the fair sex, in which he had indulged himself himself very freely.  He was survived only by one legitimate son, but left several natural children;

Our noble author has been charged by some of his enemies, with the sordid vice of covetousness, but without foundation; for, as a strong indication that he was not avaritious, he lost a considerable part of his fortune, merely by not taking the pains to visit, during the space of 40 years, his estates at some distance from London; and whoever is acquainted with human nature knows, that indolence and covetousness are incompatible.

His grace died the 24th of February 1720, in the 75th year of his age, and after lying in state for some days at Buckingham-House, was carried from thence with great funeral solemnity, and interred in Westminster-Abbey, where a monument is erected to his memory, upon which the following epitaph is engraved, by his own direction, as appears from a passage in his will.