Which country's rulers were called Tsars?

I know all about Russia and its Czars and everything else about Russia, a lot more than I care to know !! Not favorites !! 🙄🙄🙄🙄 The Austro - Hungarian Empire ?? Now we're talking !! 😃😃😃😃😃 Yellow and Black till I crack !!

Anastasia where are you?

l know

amazing the breadth of influence that Julius Caesar had.

I guessed it from Tsar bomba