I'd guess Czar Nicholas II, given the "II" on the bottom and the fact it looks like him/King George V of Great Britain (both being grandsons of Victoria, they looked so alike they often used to switch places when Nicholas visited, and no one knew who was Nicholas and who was Albert (he'd didn't change his name to George until he took the throne, in accordance with Victoria's wish no King of England be named Albert since her husband could not be king.)