Russian ruler of old

TSAR

This historical title was held by leaders like Ivan the Terrible and Peter the Great.

The clue "Russian ruler of old" points to "TSAR," the traditional title for emperors of Russia before the revolution. It’s a straightforward definition with no wordplay, relying on historical knowledge. The spelling "TSAR" is an older English transliteration of the Russian word "царь," which means "caesar" or "emperor." If you know Russian history, this one should be easy.