Complex sentence: The Battle of Resaena was fought in 243 between the forces of the Roman Empire, led by Emperor Gordian III, and a Sassanid Empire army, led by King Shapur I. Gordian III was victorious, but he died one year later.
Split into simpler sentences: The Battle of Resaena was fought in 243 between the forces of Gordian III and Persia. The Persians were led by Shapur I. Gordian III was victorious, but he died one year later.