Iconography
The person portrayed is the Roman emperor Domitian. He was the last emperor of the Flavian dynasty and reigned from 81 to 96 CE.
The collar chain described below is an overpainting. It is unclear when it was painted.
A collar chain with a head, possibly depicting the Roman sun god Sol, appears in the direct centre of the painting and on each side of the head there is a Sol symbol or a Mycenaean rosette. The collar chain with the symbols does not appear in Sadeler’s engraving or in any of the other versions of Domitian.