Complex sentence: Comyn, pg.200 The Welf duke of Saxony, Henry the Lion, would not be appeased, however, remaining an implacable enemy of the Hohenstaufen monarchy.
Split into simpler sentences: Comyn, pg.200 But the Welf duke of Saxony, Henry the Lion, would not be appeased. He remained an implacable enemy of the Hohenstaufen monarchy.