Kaloyan

Kaloyan is a 1963 Bulgarian drama film directed by Dako Dakovski.After a century of Byzantine subjugation, King Kaloyan ascends to the throne, he must implement very flexible foreign policies to strengthen his position. The forth crusade passes through his country and he beats the enemy side in a battle at Adrianople.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.