Complex sentence: He was a prolific writer of poems, allegories, fables and romances, yet his most famous works were his longer and more moralistic "Troy Book", "Siege of Thebes" and the "Fall of Princes".
Split into simpler sentences: He was a prolific writer of poems, allegories, fables and romances. His most famous works were his longer and more moralistic "Troy Book", "Siege of Thebes" and the "Fall of Princes".