Complex sentence: Poltys hosted the Heracles when he came to Aenus; although Poltys welcomed Heracles, Sarpedon did not, and was slain by Heracles on the beach.
Split into simpler sentences: Poltys hosted the hero Heracles when he came to Aenus. Although Poltys welcomed Heracles, Sarpedon did not, and was slain by Heracles on the beach.