Boatman, Yegor Ivanovich – Portrait of Alexander von Benckendorff Hermitage ~ part 02

The picture has something of this: people, wear, man, portrait, veil, weapon, outfit, sword, war, military, soldier, royalty, music, lid, helmet.
Perhaps it’s a painting of a man in a blue uniform with a feather on his left hand and a sword in his right hand, standing in front of a cloudy sky.