TIL the last Tsar of Bulgaria, Simeon II, who was forced to abdicate in 1946 also became Prime Minister in 2001

https://www.britannica.com/biography/Simeon-Saxecoburggotski

https://www.reddit.com/r/todayilearned/comments/15ldnwo/til_the_last_tsar_of_bulgaria_simeon_ii_who_was/