License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Peeter van der Borcht. Plate XII: Caesares, from "Descriptio Publicae Gratulationis Spectaculorum et Ludorum, in Advent Sereniss", 1595. The Metropolitan Museum of Art.