Complex sentence: Hugh's first wife was Isabella of La Roche, heiress of Thebes, and his second wife was Helena Komnena Dukaina of Epirus-Neopatras, heiress of Lamia and Larisa.
Split into simpler sentences: Hugh's first wife was Isabella of La Roche, heiress of Thebes. His second wife was Helena Komnena Dukaina of Epirus-Neopatras, heiress of Lamia and Larisa.