The Chasuarii were a Germanic tribe that ceased roughly in the present North Rhine Westphalia and southern Lower Saxony around the beginning of the year.
The name of this tribe is speculated. It has been suggested that the name refers to "The inhabitants of the Hase (a tributary of the Eems)". A parallel is drawn to a word like the Old English burgware "city residents" or Baiuarii "Bohemian residents" (Bohemia).
Sometimes the Chasuarii are matched with the Chattuarii.
wiki
