In January 1689 William and Mary were proclaimed joint sovereigns of England. Mary was the eldest daughter of James II and William of Orange was the great nephew of Charles I. Mary died in 1694 with William continuing as King until his death in 1702. As joint rulers they are often depicted standing side by side, sometimes within an interior, for which see an example formerly in the Gautier and Lomax Collections sold at Sotheby's London, February 19, 1991, lot 149, though more commonly the monarchs are depicted in a landscape. Due to his diminutive size ( he was five feet, six inches tall compared to his wife who was five feet eleven inches), William is often portrayed standing slightly set back from Mary so that their crowns appear on a level.
Two particularly similar dishes are illustrated by Michael Archer, Delftware in the Fitzwilliam Museum, London, 2013, pp. 9-10, A.8-A.9.