Complex sentence: In the 1950s various historical theatrical plays were written in Ethiopia about Italian invasion: among these works, Ateneh Alemu wrote a Zerai Deres' play in 1956-1957.
Split into simpler sentences: In the 1950s various historical theatrical plays were written in Ethiopia about the Italian invasion. Among these works, Ateneh Alemu wrote a play about Zerai Deres in 1956--1957.