This Roman marble sculpture is a portrait of Antinous (111-130 AD), a male youth who was a lover of the emperor Hadrian. Hadrian regularly toured the Roman Empire, and probably first encountered Antinous during a visit to Bithynia in 123 AD. Though Hadrian was married, his relationship with Antinous was in keeping with Hellenic conventions that saw older men free to pursue consensual relationships with teenage men. Antinous was deified after his death by the emperor and his image became a archetype of youthful beauty.

He is depicted wearing an ‘Attic’ helmet defined by the diadem-shaped band and the short neck guard. It is surmounted by a sphinx resting on a wedge-shaped base. The sphynx’s tail divides in two at the back and forms two scrolls on the sides of the helmet. It has been suggested that this warrior style portrait corresponds to a fashion introduced by emperor Hadrian in the 2nd century AD. Furthermore, the sphinx motif on the helmet was copied from a depiction of the emperor. The armoured bust was a later addition to match the style of the portrait.

During his reign, Charles I put together an important collection of Roman antiquities. It is believed that this portrait bust of Antinous was acquired by Charles I around 1625 and that it was one of the marble portraits from the Gonzaga collection in Mantua that were sold to Charles I by Duke Vincenzo II of Mantua.

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. 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.