Complex sentence: They were members of The Sentinent Mileu, the only race apart from the Ur-Quan which survived the dynarii empire however after freedom was gained the Ur-Quan then set out to destroy them.
Split into simpler sentences: They were members of The Sentinent Mileu, the only race apart from the Ur-Quan which survived the dynarii empire. However after freedom was gained the Ur-Quan then set out to destroy them.