License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Stefano della Bella. A commander on horseback, giving orders and motioning to the right, other horsemen in the background, two of which are engaged in a duel with pistols, from "Various cavalry exercises" (Diverses exercices de cavalerie), ca. 1642–45. The Metropolitan Museum of Art.