BERG, a duchy of Germany, in the circle of Westphalia. It is bounded on the north by the duchy of Cleves, on the west by the county of Mark and the duchy of Westphalia, on the south by Wetteravia, and on the east by the diocese of Cologne, from which it is separated by the Rhine. It contains about 1188 square miles, with 295,000 inhabitants. It is very fruitful along the Rhine, but mountainous and woody towards the county of Mark. It was formerly subject to the elector palatine, but since 1815 has been included in the grand duchy of the Lower Rhine, which belongs to Prussia. The duchy of Berg was taken from Bavaria in 1806, and bestowed upon Murat, afterwards king of Naples. It is a populous and flourishing district. The principal rivers, besides the Rhine, are the Wipper, Agger, and Sieg.