Tsar
Tsar is a title for the supreme ruler in several countries.
In Bulgaria, the title was used in 913–1422 and again in 1908–1946. The last tsar to rule Bulgaria was Boris III, who replaced Ferdinand I of Bulgaria 1918.
In Serbia, the title was used in 1346—1371. The last tsar to rule Serbia was Stephen Uroš V.
In the Russian Empire, the title was used from 1546 until 1721. Starting in 1721, the title of Russian emperors was imperator, but the word tsar remained in common use until the Russian Revolution in 1917. The last tsar to rule Russia was Nicholas II, who replaced Alexander III in 1894. The system of government used during the Tsardom of Russia and the Russian Empire was called Tsarist autocracy, also known as Tsarism.
Tsar is also spelled tzar, czar, and csar. It is the Eastern European word for caesar. It can be translated to emperor.
Tsar Media
Simeon I of Bulgaria, the first Bulgarian tsar and the first person who bore the title "tsar", by Alphonse Mucha
Reception of the Tsar of Russia in the Moscow Kremlin, by Ivan Makarov
Mostich's epitaph uses the title tsar (outlined): "Here lies Mostich who was ichirgu-boil during the reigns of Tsar Simeon and Tsar Peter. At the age of eighty he forsook the rank of ichirgu boila and all of his possessions and became a monk. And so ended his life." (Museum of Preslav)
Simeon Saxe-Coburg-Gotha is the only living person to have borne the title of "tsar" (as Simeon II of Bulgaria).
Tsar Dušan of Serbia
Nicholas II, the last Emperor of Russia.