Possible Clues:

• Nicholas I and Nicholas II
• Former Russian royals
• Bygone Russian leaders
• Nicholas II was the last of them in Russia
• Pre-1917 despots
• Autocrats of yore
• Russian rulers of yore
• 'The ___ Bride' (Rimsky-Korsakov opera)
• Some past despots
• Bulgaria's Simeon I and Simeon II