This study for a warrior on horseback has formerly been attributed to the Venetian artist, Michele Giambono, due to the general resemblance of the subject to the master’s fresco of the equestrian figure of San Crisogono (San Trovaso, Venice). However, given the differences of pose and style, the relationship is too generic to ascribe the two works to the same hand. It appears instead that both Giambono’s painted equestrian figure and this study were independently modeled on the same source: the ancient bronze horses of the Basilica of San Marco in Venice. The horse’s stance, with its raised front right leg, and head angled toward the right, as well as some anatomical details, recall the second horse from the left in the Venice group. The San Marco horses were a significant source of inspiration for equestrian imagery in the Renaissance, and artists who were not directly familiar with them may have known prototypes in the form of small statuettes.