William III (14 November 1650 – 8 March 1702) was a sovereign Prince of Orange by birth. From 1672 onwards, he governed as Stadtholder William III of Orange over Holland, Zeeland, Utrecht, Guelders, and Overijssel of the Dutch Republic. From 1689 onwards, he reigned as King William III over England and Ireland, and as King William II over Scotland. He is informally known in Northern Ireland and Scotland as "King Billy". A member of the House of Orange-Nassau, William won the English, Scottish and Irish crowns following the Glorious Revolution, in which his uncle and father-in-law James II was deposed. In England, Scotland and Ireland, William ruled jointly with his wife, Mary II, until her death on 28 December 1694.
A Protestant, William participated in several wars against the powerful Catholic King Louis XIV of France in coalition with Protestant and Catholic powers in Europe. Many Protestants heralded him as a champion of their faith. Largely due to that reputation, William was able to take the British crowns when many were fearful of a revival of Catholicism under James. William's victory over James II at the Battle of the Boyne in 1690 is commemorated by the Orange Institution in Northern Ireland to this day. His reign marked the beginning of the transition from the personal rule of the Stuarts to the more Parliament-centred rule of the House of Hanover.
William Henry of Orange, the only child of stadtholder William II, Prince of Orange and Mary, Princess Royal of England, was born in The Hague in the Dutch Republic on 14 November 1650. Eight days before William's birth, his father died from smallpox; thus William was the Sovereign Prince of Orange from the moment of his birth. Immediately a conflict ensued between the Princess Royal and William II's mother, Amalia of Solms-Braunfels, over the name to be given to the infant. Mary wanted to name him Charles after her brother, but her mother-in-law insisted on giving him the name William or Willem to bolster his prospects of becoming stadtholder. William II had appointed his wife as his son's guardian in his will; however the document remained unsigned at William II's death and was void. On 13 August 1651 the Dutch Hoge Raad (Supreme Council) ruled that guardianship would be shared between his mother, his paternal grandmother and Frederick William, the Elector of Brandenburg, whose wife, Louise Henriette, was his father's eldest sister.