_"Czar" or "Tsar."_--Whence the derivation of the title _Czar_ or _Tsar_?
I know that some suppose it to be derived from Cæsar, while others trace
it from the terminal _-sar_ or _-zar_ in the names of the kings of
Babylon and Assyria: as Phalas-_sar_, Nebuchadnez-_zar_, &c. In Persian,
_sar_ means the supreme power. I have heard much argument about its
origin, and would be much obliged if any reader of "N. & Q." could state
the correct derivation of the word.
By which Emperor of Russia was the title first assumed?