In 1677, he married his first cousin Mary, the elder daughter of his maternal uncle James, Duke of York, the younger brother and later successor of King Charles II.

[5] On 13 August 1651, the Hoge Raad van Holland en Zeeland (Supreme Court) ruled that guardianship would be shared between his mother, his grandmother and Frederick William, Elector of Brandenburg, husband of his paternal aunt Louise Henriette.

[6] William's education was first laid in the hands of several Dutch governesses, some of English descent, including Walburg Howard[7] and the Scottish noblewoman Lady Anna Mackenzie.

[8] From April 1656, the prince received daily instruction in the Reformed religion from the Calvinist preacher Cornelis Trigland, a follower of the Contra-Remonstrant theologian Gisbertus Voetius.

[12][13][14][15] From early 1659, William spent seven years at the University of Leiden for a formal education, under the guidance of ethics professor Hendrik Bornius (though never officially enrolling as a student).

On 23 December 1660, when William was ten years old, his mother died of smallpox at Whitehall Palace, London, while visiting her brother, the recently restored King Charles II.

[23] De Witt, the leading politician of the Republic, took William's education into his own hands, instructing him weekly in state matters and joining him for regular games of real tennis.

[f] At the demand of Oliver Cromwell, the Treaty of Westminster, which ended the First Anglo-Dutch War, had a secret annexe that required the Act of Seclusion, which forbade the province of Holland from appointing a member of the House of Orange as stadtholder.

[26] The Edict, supported by the important Amsterdam politicians Andries de Graeff and Gillis Valckenier,[27] declared that the Captain-General or Admiral-General of the Netherlands could not serve as stadtholder in any province.

[26] William saw all this as a defeat, but the arrangement was a compromise: De Witt would have preferred to ignore the prince completely, but now his eventual rise to the office of supreme army commander was implicit.

[49] Fagel now proposed to treat the liberated provinces of Utrecht, Gelderland and Overijssel as conquered territory (Generality Lands), as punishment for their quick surrender to the enemy.

[52] Baruch Spinoza's warning in his Political Treatise of 1677 of the need to organize the state so that the citizens maintain control over the sovereign was an influential expression of this unease with the concentration of power in one person.

The Dutch were split by internal disputes; the powerful Amsterdam mercantile body was anxious to end an expensive war once their commercial interests were secured, while William saw France as a long-term threat that had to be defeated.

[57] The peace talks that began at Nijmegen in 1676 were given a greater sense of urgency in November 1677 when William married his cousin Mary, Charles II of England's niece.

Louis seized this opportunity to improve his negotiating position and captured Ypres and Ghent in early March, before signing a peace treaty with the Dutch on 10 August.

[70] Nevertheless, William secretly induced the States General to send Charles the "Insinuation", a plea beseeching the king to prevent any Catholics from succeeding him, without explicitly naming James.

[77] In June, Mary of Modena, after a string of miscarriages, gave birth to a son, James Francis Edward Stuart, who displaced William's Protestant wife to become first in the line of succession and raised the prospect of an ongoing Catholic monarchy.

William's fleet was vastly larger than the Spanish Armada 100 years earlier: approximately consisting of 463 ships with 40,000 men on board,[82] including 9,500 sailors, 11,000 foot soldiers, 4,000 cavalry and 5,000 English and Huguenot volunteers.

[88] William felt insecure about his position; though his wife preceded him in the line of succession to the throne, he wished to reign as king in his own right, rather than as a mere consort.

Thus concluded the Williamite pacification of Ireland, and for his services, the Dutch general received the formal thanks of the House of Commons and was awarded the title of Earl of Athlone by the king.

[102][103] Bowing to public opinion, William dismissed those responsible for the massacre, though they still remained in his favour; in the words of the historian John Dalberg-Acton, "one became a colonel, another a knight, a third a peer, and a fourth an earl.

Some believe there may have been truth to the rumours,[127] while others affirm that they were no more than figments of his enemies' imaginations, as it was common for someone childless like William to adopt, or evince paternal affections for, a younger man.

As his life drew towards its conclusion, William, like many other contemporary European rulers, felt concern over the question of succession to the throne of Spain, which brought with it vast territories in Italy, the Low Countries and the New World.

Charles II of Spain was an invalid with no prospect of having children; some of his closest relatives included Louis XIV of France and Leopold I, Holy Roman Emperor.

William and Louis agreed to the First Partition Treaty (1698), which provided for the division of the Spanish Empire: Joseph Ferdinand, Electoral Prince of Bavaria, would obtain Spain, while France and the Holy Roman Emperor would divide the remaining territories between them.

[139] As the complete exhaustion of the defined line of succession would have encouraged a restoration of James II's line, the English Parliament passed the Act of Settlement 1701, which provided that if Anne died without surviving issue and William failed to have surviving issue by any subsequent marriage, the Crown would pass to a distant relative, Sophia, Electress of Hanover (a granddaughter of James I), and to her Protestant heirs.

Another important consequence of William's reign in England involved the ending of a bitter conflict between Crown and Parliament that had lasted since the accession of the first English monarch of the House of Stuart, James I, in 1603.

British historian John Childs acknowledges William's great qualities, but feels that he fell short as a field commander because, by often throwing himself into the fray, he no longer had the complete oversight.

[156] The Dutch East India Company built a military fort in Cape Town, South Africa, in the 17th century, naming it the Castle of Good Hope.

[157] By 1674, William was fully styled as "Willem III, by God's grace Prince of Orange, Count of Nassau etc., Stadtholder of Holland, Zeeland, Utrecht etc., Captain- and Admiral-General of the United Netherlands".