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. Several horses fighting, one horse to right kicking two horses on the ground below to left, other horses fighting in the background, from "Various cavalry exercises" (Diverses exercices de cavalerie), ca. 1642–45. The Metropolitan Museum of Art.