This portrait is of a heavy-looking man, clean-shaven and with short, curling hair. Very similar portraits on coins indicate that the man is Philetairos, the eunuch ruler of Pergamon (Pergamum) and founder of the Attalid dynasty. Under Philetairos the city of Pergamon became a great cultural and political centre. The engraving may have been executed in Philetairos' own lifetime; however, as his portrait appears on the coins of several of his successors and his appearance is likely to have been well known in Pergamon, the seal-stone may date to the later third or early second century BC. In the Hellenistic period, it became common for rulers of the separate Hellenistic kingdoms to have their own images, whether realistic or idealised, engraved on seal-stones. This fashion appears to have started with Alexander the Great, who is said to have granted the seal-engraver Pyrgoteles a monopoly in portraying the royal image in this medium. Like earlier Archaic and Classical Greek seals, many Hellenistic examples would have been set into rings and used both as jewellery and as a mark of possession or identity. The fashion for wealthy individuals to form collections of fine examples of gems is first seen at this time.