Related Clues:

• Bygone sovereign
• Russian Revolution victim (Var.)
• Pre-Soviet ruler (Var.)
• Studio head (Var.)
• Alexandra's husband (Var.)
• Male monarch (Var.)
• Boris Godunov, for one (Var.)
• Simeon I, for one (Var.)
• 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.)