This is a smaller and inferior version of a full-length portrait of which two autograph versions are known, both signed and dated 1751, one in the Mauritshuis and one in the Rijksmuseum. The sitter (who is shown in armour with the riband and star of the Order of the Garter and a red sash at his waist) was the eldest son and heir of John William Friso, who succeeded William III as Prince of Orange and effective Dutch ruler in 1701 (though descended from the brother of William the Silent rather than the 'Founder of the Nation' himself). In 1734 William IV maried Princess Anne (George II's daughter); the official title of 'Hereditary Stadtholder of the Netherlands' was conferred upon him in 1748; he also formed an important art collection. All these things played a part in the process of elevating the House of Orange to quasi-royal status.