Sir Godfrey Kneller (1646–1723) was born Gottfried Kniller in Lübeck, trained in Amsterdam under Ferdinand Bol with some contact with Rembrandt's circle, studied in Rome and Venice, and arrived in England in 1676. He was appointed Principal Painter to Charles II in 1679 and held the post, in effect, under James II, William and Mary, Anne and George I — knighted in 1692, made a baronet in 1715. No English portraitist before or since held the position so long.

The studio was the mechanism that made this possible. Working from Great Queen Street in London, and later from his house at Whitton, Kneller ran what amounted to a portrait manufactory. Sitters came for a single sitting, usually short; Kneller drew and painted the head, then handed the canvas to assistants who executed the drapery, hands, background and accessories from established patterns. Specialist drapery painters were employed for this alone. The output was enormous — several thousand portraits — and the studio's function was as much reproductive as creative: royal likenesses were needed in quantity for embassies, guildhalls, colleges, county families and loyal subjects, and the same head was repeated dozens of times over.

He trained or employed a long list of assistants, among them Edward Byng, who kept the studio's pattern drawings, and Kneller ran an academy in Great Queen Street from 1711, the first formal drawing school in London and a direct ancestor of the Royal Academy.

"Studio of Kneller" therefore means something specific: a replica produced in the workshop during his lifetime, from his design, under his supervision, but not by his hand — the mechanism by which the face of William III reached the walls of Britain.