 Since 1943 he was one of four staff officers who coordinated military activities of international groups in non-occupied France that were incorporated into the French Forces of the Interior ("FFI").Gaining a rank of Captain of "FFI", he was in command of 1,200-strong group of non-French militias in Paris region.During his stay in Paris, Hromádko fell in love with Věra Waldes, a daughter of wealthy Czech industrial family.