Complex sentence: Desilu Productions was a Los Angeles, California-based company jointly owned by actors Desi Arnaz and Lucille Ball, who were married to each other from 1940 to 1960.
Split into simpler sentences: Desilu Productions was a Los Angeles, California-based company jointly owned by Desi Arnaz and Lucille Ball. Both Arnaz and Ball were married to each other from 1940 to 1960.