This Head of an Idealized Female with a Diadem was acquired by Charles I. In a period when collecting antiquities became fashionable - although it remained exclusive to the very wealthiest because of the cost and rarity of the pieces - Charles I intended to imitate the grand collections of Renaissance princes in the continent. This marble portrait was possibly acquired on behalf of Charles I by Sir Kenelm Digby in Asia Minor.

It has been suggested that because of its stereotyped and idealised features this was likely to be an ordinary commission rather than a specific private request. This female is depicted with a plain tapering diadem tied with a fillet at the back. The hair is parted in the middle and swept to the sides in an undulating wavy pattern. The hairstyle and the applied chiselling technique suggest that it possibly dates from the middle of 2nd century AD. The head has been joined by a restorer to a bust of larger proportions but matching style. It is dressed with a tunic with a mantle on top folded to make a V-shape and fastened with a brooch on the shoulders.

During his reign, Charles I put together an important collection of classical antiquities. Five outstanding Roman marble portrait busts (RCIN 1296, 1297, 1298, 1299 and 1300) dating from the 2nd century AD, which once belonged to Charles I, remain today in the Royal Collection.