Related Clues:

• Russian monarch
• Ruler of yore
• Head boss
• Peter the Great, for one
• Energy ___
• Nicholas II, for one
• 4-Down, e.g.
• Industrial mogul, e.g.
• Commercial bigwig
• Father of a grand duke
• Industry kingpin
• Peter I, e.g.
• Autocrat of old
• Old Russian ruler
• Drug ___