William III on a grey charger observed by Neptune, Ceres and Flora. Mercury in the sky and Astrea Sir Godfrey Kneller (1646-1723)

The picture has something of this: cavalry, people, seated, mammal, veil, woman, group, sword, lid, herder, Renaissance, man, baby, cape, weapon.
Perhaps it’s a painting of a woman riding on the back of a white horse with angels above her and a child sitting.