William was at first opposed to the project of invasion. Meanwhile, in England, James II's second wife, Mary of Modena, bore a son (James Francis Edward), who displaced William's wife to become first in the line of succession. Public anger was also inspired by the trial of seven bishops who had publicly opposed James II's religious policies and had petitioned him to reform them. The acquittal of the bishops signalled a major defeat for the Government of James II, and encouraged further resistance to its activities.

Still, William was reluctant to invade, believing that the English People would not react well to a foreign invader. He therefore demanded that the most eminent English Protestants first invite him to invade. On 30 June 1688—the same day the bishops were acquitted—a group of political figures known as the "Immortal Seven" complied, sending him a formal invitation. William began to make preparations for an invasion; his intentions were public knowledge by September 1688. With a Dutch army, William landed in England on 5 November 1688. James's support dissolved almost immediately.  Protestant officers defected from the English army, and influential noblemen across the country declared their support for the invader. Though the invasion and subsequent overthrow of James II is commonly known as the "Glorious Revolution," it was in reality a coup d'état.

James at first attempted to resist William, but saw that his efforts would prove futile. He sent representatives to negotiate with William, but secretly attempted to flee on 11 December. He was caught by a group of fishermen, brought back to London, but successfully attempted to escape on 23 December. William actually permitted James to leave the country, for he did not wish to make him a martyr for the Roman Catholic cause.

In 1689, a Convention Parliament summoned by the Prince of Orange assembled, and much discussion relating to the appropriate course of action ensued. William III was insecure about his position; he wished to be King in his own right, rather than a mere consort.  William demanded that he be King even after his wife's death. Although some individuals proposed to make her the sole ruler, Mary, remaining loyal to her husband, refused.

On 13 February 1689, Parliament passed the Declaration of Right, in which it deemed that James had abdicated the government of the realm and that the Throne was thereby vacant. The Crown was not offered to James's eldest son, James Francis Edward (who would have been the heir-apparent under normal circumstances), but to William and Mary as joint Sovereigns. It was, however, provided that "the sole and full exercise of the regal power be only in and executed by the said Prince of Orange in the names of the said Prince and Princess during their joint lives."

William and Mary were crowned together at Westminster Abbey on 11 April 1689 by the Bishop of London.  Normally, the coronation is performed by the Archbishop of Canterbury, but the Archbishop at the time did not recognise James II's removal. On the day of the coronation, the Convention of the Estates of Scotland  finally declared that James was no longer King of Scotland. William and Mary were offered the Scottish Crown; they accepted on 11 May. William was officially "William II," for there was only one previous Scottish King named William.

In December 1689, one of the most important constitutional documents in English history, the Bill of Rights, was passed. The Act established restrictions on the royal prerogative; it was provided, amongst other things, that

-the Sovereign could not suspend laws passed by Parliament

-levy taxes without parliamentary consent

-infringe the right to petition

-raise a standing army during peacetime without parliamentary consent,

-deny the right to bear arms to Protestant subjects

-unduly interfere with parliamentary elections

-punish members of either House Parliament for anything said during debates

-require excessive bail or inflict cruel or unusual punishments.

William was opposed to the imposition of such constraints, but he wisely chose not to engage in a conflict with Parliament and agreed to abide by the statute.

The Bill of Rights also settled the question of succession to the Crown. After the death of either William or Mary, the other would continue to reign. Next in the line of succession was Mary II's sister, the Princess Anne, and her issue. Finally, any children William might have had by a subsequent marriage were included in the line of succession. Non-Protestants, as well as those who married Roman Catholics, were excluded from the succession.

Mary II died of smallpox in 1694, leaving William to rule alone.  Although he had previously mistreated his wife and kept mistresses, William deeply mourned his wife's death. Although he was brought up as a Calvinist, he converted to Anglicanism. His popularity, however, plummetted during his reign as a sole Sovereign.The War of the Spanish Succession, however, was not the only thing that concerned William.  His marriage with Mary II had not yielded any children, and he did not seem likely to remarry. Mary's sister, Princess Anne, had borne numerous children, all of whom died during childhood. The death of William, Duke of Gloucester in 1700 left the Princess Anne as the only individual left in the line of succession established by the Bill of Rights. As the complete exhaustion of the line of succession would have encouraged a restoration of James II's line, Parliament saw fit to pass the Act of Settlement 1701, in which it was provided that the Crown would be inherited by a distant relative, Sophia, Electress of Hanover and her Protestant heirs if the Princess Anne died without surviving issue, and if William III failed to have surviving issue by any subsequent marriage. (Several Roman Catholics with genealogically senior claims to Sophia were omitted.) The Act extended to England and Ireland, but not to Scotland, whose Estates had not been consulted before the selection of Sophia.

Like the Bill of Rights before it, the Act of Settlement not only addressed succession to the Throne, but also limited the power of the Crown. Future Sovereigns were forbidden to use English resources to defend any of their other realms, unless parliamentary consent was first obtained. To ensure the independence of the judiciary, it was enacted that judges would serve during good behaviour, rather than at the pleasure of the Sovereign. It was also enacted that a pardon issued by the Sovereign could not impede an impeachment.

Death

In 1702, William-who did not remarry-died of complications resulting from a fall off his horse. It was believed by some that his horse had stumbled into a mole's burrow and as a result many Jacobites toasted "the little gentleman in the black velvet waistcoat."

William was buried in Westminster Abbey alongside his wife. The reign of William's successor, Anne, was marked by attempts to extend the provisions of the Act of Settlement to Scotland. Angered by the English Parliament's failure to consult with them before choosing Sophia of Hanover, the Estates of Scotland enacted the Act of Security, forcing Anne to grant the Royal Assent by threatening to withdraw troops from the army fighting in the War of the Spanish Succession. The Act provided that, if Anne died without a child, the Estates could elect the next monarch from amongst the Protestant descendants of previous Scottish Kings, but could not choose the English successor unless various religious, political and economic conditions were met. In turn, the English Parliament attempted to force the Scots to capitulate by restricting trade, thereby crippling the Scottish economy. The Scottish Estates were forced to agree to the Act of Union 1707, which united England and Scotland into a single realm called Great Britain.  Succession was to be under the terms established by the Act of Settlement.

William's death also brought an end to the Dutch House of Orange, which had governed the Netherlands since the time of William the Silent (William I). The five provinces over which William III ruled-Holland, Zeeland, Utrecht, Gelderland and Overijssel-all suspended the office of Stadtholder after William III's death. The remaining two provinces-Friesland and Groningen-were never governed by William III, and continued to retain a separate Stadtholder.