The Battle of Wagram, July 6th 1809 (detail) Horace Vernet (1789-1863)

The picture has something of this: cavalry, people, seated, mammal, group, military, weapon, man, wear, war, army, gun, skirmish, soldier, veil, many, lid, battle.
Perhaps it’s a painting of a man riding on the back of a white horse next to a group of men.