Complex sentence: In the 13th and 14th centuries the City of Düsseldorf grew on the grounds of the Knights Hayc von Flingern and by the end of the 14th century the knights lost their influence.
Split into simpler sentences: In the 13th and 14th centuries the City of Düsseldorf grew on the grounds of the Knights Hayc von Flingern. By the end of the 14th century the knights lost their influence.