Related Clues:

• Peter or Paul, e.g. (Var.)
• Energy ___
• Ruler of yore (Var.)
• Word derived from 10-Down
• Ruler opposed by the Bolsheviks
• Peter or Nicholas
• Russian monarch, once (Var.)
• Royal Russian (Var.)
• Romanov title (Var.)
• Tough boss
• Peter or Ivan, e.g. (Var.)
• Former Winter Palace resident
• Boris Godunov, e.g.
• Old totalitarian ruler
• Alexander, e.g.