This head and arm were part of a statue of Domitian that stood to a height of 23 ft. [7 m.]. The statue stood in the temple of the Flavian Sebastoi, often called the Temple of Domitian that stood on a platform on the west end of the Civic Agora of Ephesus.
The temple, built during the reign of Domitian, was dedicated to Vespasian (his father), Titus (his brother), and himself. "Flavian" is their family name while "sebastoi" means the "revered ones."