Complex sentence: At various times Maurice Sand, Ary Scheffer, Charles Gounod, Hector Berlioz were in relationships with Pauline Viardot--in letters they claimed that they were in love with her.
Split into simpler sentences: At various times Maurice Sand, Ary Scheffer, Charles Gounod, Hector Berlioz were in relationships with Pauline Viardot. In letters they claimed that they were in love with her.