His full name was Bohdan Zynoviy Mykhailovych Khmelnysky (Polish: Bohdan Zenobi Chmielnicki)
As it was custom in the Greek Orthodox Church, he was baptized by one of his middle names - Theodor, translated into Ukrainian has Bohdan.
Although the hetman was the highest military office and head of state in the Cossack Hetmanate, it was the second-highest military commander, after the monarch, in the Polish Commonwealth. Therefore, Khymelnystky was technically not a monarch.