Marya Morevna: Russian Folk Fairy Tales

Marya Morevna is a Russian fairy tale collected by Alexander Afanasyev in Narodnye russkie skazki. 
Marya was a warrior queen who ruled a small kingdom and for some 10 years, kept Koschei the Deathless a captive in her castle's tower. The character Koschei is an evil immortal man who menaces young women with his magic.She fell in love with Ivan Tsarevitch, and while she was away on a campaign, he accidentally released Koschei. The evil wizard then abducted the queen and Ivan Tsarevitch was forced to find some way to kill him. Ivan was successful and was reunited with Marya. The two of them were married and their kingdoms became united.