What is "dreingau"

Dreingau is the medieval name of one of five Saxon pagi (i.e., boroughs) in what today is the Münsterland in Westphalia. During the Middle Ages documents referred to it as Dreine, Dreni, Drieni, Dragini, Dragieni, Drachina or Treine. The name came into use around the year 800, and is hardly used anymore today. It has survived only in the name of the town Drensteinfurt, and in the name of a regional newspaper, the Dreingau-Zeitung.