Complex sentence: According to Ovid ("Metamorphoses" V, 551), the Sirens were the companions of young Persephone and were given wings by Demeter to search for Persephone when she was abducted.
Split into simpler sentences: According to Ovid ("Metamorphoses" V, 551), the Sirens were the companions of young Persephone. They were given wings by Demeter to search for Persephone when she was abducted.