Frances Villiers, Countess of Jersey his "wife", Maria Fitzherbert, with whom he had undergone a form of marriage in a clandestine Church of England ceremony that all parties to it knew was invalid under the Royal Marriages Act 1772. Having encouraged the Prince of Wales to marry his first cousin, Caroline of Brunswick in 1794, Lady Jersey nevertheless set out to make Caroline's life difficult. However, the now Princess of Wales (Caroline) had very little regard for George IV, nor he for her, and after the birth of their child, they lived apart during their twenty-five year marriage, leaving a void Frances and other mistresses,
John Villiers, 1st Viscount Purbeck remained strongly opposed to the marriage, but Coke gave way, and on 29 September 1617 Frances Coke and Sir John Villiers were married at Hampton Court, with King James giving away the bride. Lady Hatton still refused to make over her Dorset property to Villiers, and as compensation he was created Baron Villiers of Stoke (today Coleshill, Buckinghamshire), and Viscount Purbeck of Dorset on 19 July 1619. The marriage proved a disaster; Anthony Weldon reports Buckingham as having said that "his brother Purbeck had more wit and honesty than all the kindred beside", but according to Samuel Rawson Gardiner, he