Bygone Leader is a term that refers to a leader from the past, such as a monarch or ruler. The two crossword solutions for this term are SHAH and TSAR. A SHAH is a title given to the monarch of Iran, and it is derived from the Persian word for king. A TSAR is a title given to the monarch of Russia, and it is derived from the Latin word for Caesar. Both titles refer to powerful rulers who have since been replaced by other forms of government.