How many movies have Bogomil Simeonov and Plamen Donchev acted in together?

They have worked on 4 movies together! Their first movie together was Kaloyan (1963) while their highest rated movie together was Khan Asparukh - Part III - Land Forever (1981). They have not worked together since Khan Asparukh - Part I - Phanagoria (1981). They are most known for their history films together.