Tsar

Tsar (/zɑːr, sɑːr/ or /tsɑːr/), also spelled czar, tzar, or csar, is a title used to designate East and South Slavic monarchs. In this last capacity it lends its name to a system of government, tsarist autocracy or tsarism. The term is derived from the Latin word caesar, which was intended to mean "emperor" in the European medieval sense of the term—a ruler with the same rank as a Roman emperor, holding it by the approval of another emperor or a supreme ecclesiastical official (the Pope or the Ecumenical Patriarch)—but was usually considered by western Europeans to be equivalent to "king".
In Depression People, it is and only has been in use by one country:
Vyščínian Union of Sovereign Polities (Squall and Wyspy Elblągskiej Imperium Nova)
The current and only holder of the title of "Tsar" is e34. To see more info on the Tsar of the Vyščínian Union, visit that page.