Related Clues:

• Pre-1917 ruler
• Nicholas was one
• Figure in a Rimsky-Korsakov opera
• Enter, as data
• Listing
• Russian autocrat
• Register
• Bygone leader
• Travel account
• Nicholas I or II, e.g.
• See 17-Across
• Detailed account
• Opera 'The Tale of ___ Saltan'
• Nicholas or Alexander
• Paul I, e.g.