Born in The Hague to Louis of Nassau-Beverweerd (illegitimate son of Maurice of Nassau, Prince of Orange) and his wife Isabella van Hoorn, Overkirk was baptised there on 16 December 1640.

Overkirk died on 18 October 1708 at Roeselare in modern-day Belgium and is buried the Nassau-LaLecq Crypt at Ouderkerk aan den IJssel, Netherlands.

Prince William, who himself was fighting in the thick of the action, was so close to the enemy that the knight d'Esclainvilliers was already putting a gun to his chest when Ouwerkerk shot the Frenchman out of his saddle.

The next year Overkirk achieved great fame as colonel of the Dutch bodyguard at the Battle of Landen, where he overran two French squadrons, passed through a third and obtained some standards and prisoners.

In England, he met the Duke of Marlborough, under whom, and possibly on whose recommendation, he was appointed field marshal of the whole Dutch States Army during the War of the Spanish Succession, after the Earl of Athlone died.

In the campaign of 1704, Marlborough marched with a part of the Allied troops to the Danube to support the Holy Roman Emperor and fought the Battle of Blenheim there.

The next year Overkirk had a major role in the victory at the Battle of Ramillies, where he fought in person at the head of the cavalry on the left wing.

Their children included: Reinildis van Ditzhuyzen, Oranje-Nassau: Een biografisch woordenboek, Haarlem 2004, 122-124 (with a portrait by G. Kneller, Oranje Nassau Museum)