A Mounted Officer Jean Baptiste Édouard Detaille (1848-1912)

The picture has something of this: cavalry, people, military, seated, man, soldier, mammal, army, weapon, transportation system, two, wear, group, war, sword, lid, rider, gun, uniform.
Perhaps it’s a painting of a man sitting on top of a horse next to a crowd of people on the other side of the painting is a man on a horse.