WESTPHALIA, formerly a duchy of Germany, bounded to the east by the bishopric of Paderborn, and the territories of Waldeck and Hesse; to the south by the counties of Witgenstein and Nassau, and the duchy of Berg; to the north by the bishopric of Munster and the county of Lippe. It is about 40 miles in length and 30 in breadth. The lower part of it is very fruitful, yielding plenty of corn and cattle, and some salt springs. The higher affords iron ore, calamine, lead, copper, some silver and gold, fine woods, cattle, game, fish, with a little corn. The rivers, that either pass through the duchy or along its borders, are the Rhine, the Lenne, the Bigge, the Dimel, and the Lippe. There are 28 towns in it, besides boroughs and cloisters. The provincial diets are held at Arensberg. In the year 1180, the emperor Fred. I. made a donation of this duchy to the archbishopric of Cologne, which was confirmed by succeeding emperors; and in 1638, the last duke of Arensberg ceded to it also the county of Arensberg.