On the 4th of November 1677, Henry Compton, Bishop of London, married Princess Mary, the fifteen-year-old elder daughter of James, Duke of York, to her first cousin William III of Orange, Stadholder of the Dutch Republic. The ceremony took place privately in Mary's bedchamber at St James's Palace. Contemporary accounts record that the princess wept on learning of the match, and the union appears to have been received with little enthusiasm on either side. It nevertheless proved to be one of the most consequential dynastic marriages in English history.

The arrangement was initially driven by foreign policy. The Dutch Republic had been at war with Louis XIV since 1672, and William sought to detach England from its alignment with France. In London, the Earl of Danby promoted the marriage as a means of reassuring Protestant opinion, which had grown uneasy at Charles II's French sympathies and at the open Catholicism of the Duke of York. Charles consented in part to strengthen his position in negotiations with Louis, who is reported to have received the news with displeasure.

The longer-term significance of the marriage became apparent only after 1685. Mary had been raised a Protestant at Charles's direction, and in the absence of a son she remained heir presumptive to her father. As James II pursued policies favourable to Catholics, Protestant opposition increasingly regarded Mary, and by extension William, as the guarantors of the established Church. The birth of James Francis Edward Stuart in June 1688 displaced Mary in the succession and contributed directly to the invitation that brought William to Torbay that November. Following James's flight, Parliament offered the crown jointly to William and Mary in February 1689.