Van Dyck’s celebrated Equestrian Portrait of Charles I (or Charles I on Horseback), now in the National Gallery, London, was painted for the king in about 1637–8 (fig. 1). It also exists in a smaller version (Royal Collection Trust; fig. 2), of which the Trewithen picture is a highly competent copy.¹ The National Gallery and Royal Collection compositions differ in several respects, and in nearly every instance of difference the Trewithen portrait more closely resembles the Royal Collection version: in details of the foreground and in the wood, the form of the canopy of leaves, the positioning of the dead tree on which the tablet is propped and in the attendant’s figure and the helmet. A great many copies of the Royal Collection picture are recorded, some of which were apparently painted in the eighteenth century and later. Good copies include those at Abercairny House, Audley End, Ashburnham Place, Warwick Castle and in the Clarendon Collection.² In 1829 the present picture was displayed in the Saloon, and in 1928 in the Nursery Corridor.