Complex sentence: Giacomo Puccini's only son, Antonio, had no children by his wife, but fathered an illegitimate daughter, Simonetta Giurumello, who was born in 1929.
Split into simpler sentences: Giacomo Puccini's only son, Antonio, had no children by his wife. His illegitimate daughter, Simonetta Giurumello, was born in 1929.