Felix gem (popular). Famous Roman gem with scenes from the Trojan Wars, Diomedes, and Odysseus, Roman, 1st half of the 1st century CE. Sardonyx, 3.5cm (length); 2.65cm (width); 3.22g (weight). Purchased, 1966, AN1966.1808 © Ashmolean Museum, University of Oxford

This gem was originally owned by a Roman official named Calpurnius Severus, whose name is inscribed in Greek at the top. He may have been a member of the court of the Emperor Tiberius (r. AD 14–37). The engraved phrase ‘Felix made this’ also in Greek gives us the name of its maker. Many skilled craftsmen were from the Greek east of the Roman Empire

Engraved gems, known as intaglios or sealstones, were worn as decoration and used as a device to make an identifying mark in wax. They are often decorated with subjects of significance to the owner. The scene depicted on this example is the Theft of the Palladion during the Trojan War. A prophesy had revealed that the Greeks could only capture Troy if the cult statue of the goddess Athena (known as the Palladion) was in their procession. The hero Diomedes is shown on the right clutching the Palladion but in order to claim it he has killed the temple guard. His feet are just visible on the ground below the bearded hero Odysseus, who gestures in horror at this act of sacrilege. The gods were so angered that many Greek warriors were killed before or during their return journey home to Greece.

The Felix Gem was clearly a luxury item in Roman times and since the Roman Empire it has been in the possession of many prominent collectors and members of the European nobility, including Popes and Kings. It came to the Ashmolean, however, through its association with Thomas Howard, 2nd Earl of Arundel. He bought the intaglio in the 1630s as part of a gem cabinet costing £10,000, a huge sum at that time.