Complex sentence: The town had a significant contribution to the religious struggles during the Renaissance--in the 19th century the active and public-spirited citizens of Karnobat expelled the bishop of Anhialo and in this way they completely eliminated the Greek influence.
Split into simpler sentences: The town had a significant contribution to the religious struggles during the Renaissance. In the 19th century the citizens of Karnobat expelled the bishop of Anhialo and so completely eliminated the Greek influence.