Complex sentence: The rise of the Sassanid dynasty in Persia damaged the Palmyrene trade considerably, the Sassanids disbanded the Palmyrene colonies in their lands, and started a full scale war against the Roman empire.
Split into simpler sentences: The rise of the Sassanid dynasty in Persia damaged the Palmyrene trade considerably. The Sassanids disbanded the Palmyrene colonies in their lands, and started a full scale war against the Roman empire.