Johann Georg Ziesenis

In 1763 Frederick the Great's sister, the Duchess of Brunswick, commissioned a portrait of the Prussian king from Johann Georg Ziesenis, and the king may have sat for it at her palace of Salzdahlum that June. In 1913 a historian claimed it was the only portrait Frederick had ever sat for. The claim is now doubted, and the smooth, youthful face hardly matches the king's own letters of those months, where he complained of being thin, fragile and grey.

Ziesenis was born in Copenhagen in 1716, the son of a painter from Hanover, learned from his father and trained further in Düsseldorf. His career moved from court to court. He was court painter in Zweibrücken and then in Mannheim, and from 1760 he served the court of Hanover, whose electors were also kings of Great Britain. He also painted Sophie Charlotte of Mecklenburg-Strelitz as a young princess, before she married George III, and that picture is now in the Royal Collection.

In 1768 he joined the painters' guild in The Hague while working for the young stadholder William V and his family. He made about 260 works, nearly all portraits, and died in Hanover in 1776.