a small town of Germany, in the circle of Westphalia, defended by a castle. It is the capital of a county of the same name, and was erected into a principality by the emperor Maximilian II. in favour of John de Ligne, lord of Barbazon, who took the name of Aremberg. It is seated on the river Aer.

E. Long. 7. 3. N. Lat. 50. 27.