Nicholas II, for one (4)
I believe the answer is:
tsar
(Other definitions for tsar that I've seen before include "Title of Russian emperor" , "Despot" , "Supremo" , "Russian monarch" , "Title given to the kings of Bulgaria" .)
I believe the answer is:
tsar
(Other definitions for tsar that I've seen before include "Title of Russian emperor" , "Despot" , "Supremo" , "Russian monarch" , "Title given to the kings of Bulgaria" .)