License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Adriaen Collaert. Plate 12: equestrian statue of Domitian, seen three-quarters to the left, with his stabbing death at right in the background, from 'Roman Emperors on Horseback', ca. 1587–89. The Metropolitan Museum of Art.