great hall or a palas to be able to accommodate the emperor and his retinue for a limited time. Illustrative examples of such residence castles are the Electorate of Cologne's Lechenich Castle, Jülich's Brüggen Castle and the castles of Angermund in the eponymous quarter of Düsseldorf and Windeck Castle, which belonged to the Count of Berg. Several Landesburgen had still other functions: they served as a mints, toll castles, supply depots or harbour castles, and were therefore of great financial and economic importance, not just for the surrounding castle estates, settlements and towns, but also for the whole princely territory. After the expansion of territory in the large principalities, many Landesburgen served primarily to securing their borders. The archbishops of Cologne, for example, surrounding their whole territory with strong border fortresses. For example, Linn Castle was built in today's Krefeld to counter the predations of the dukes of Cleves, the counts of Moers and the counts of Berg. Kempen Castle protected the Electorate of Cologne's area to the northwest, while Lechenich and Zülpich were built to defend against the strongest rival of the Electorate of Cologne, the counts of Jülich. Andernach Castle, however, was built for the defence of the state against the Electorate of Trier. Landesburgen emerged in the 14th century and were often built on the foundations of earlier fortifications that had been destroyed or fallen into ruin. These castles were typically much larger than their predecessors. They were constantly expanded and modernized in order to be prepared for the latest weapons technology and to meet the needs of the time. Landesburgen were often integrated into the fortifications of a town or city, using and reinforcing the existing defences. This is clearly visible in, for example, the castles of Andernach, Kempen and Rheinbach. References Literature Horst Wolfgang Böhme, Reinhard Friedrich, Barbara Schock-Werner (eds.): Wörterbuch der Burgen, Schlösser und Festungen. Philipp Reclam, Stuttgart 2004, , pp. 175, 241. Stefan Frankewitz: Geldrische Landesburgen vom 13. bis zum Ende des 15. Jahrhunderts. In: Johannes Stinner, Karl-Heinz Tekath (eds.): Gelre – Geldern – Gelderland. Geschichte und Kultur des Herzogtums Geldern . Verlag des Historischen Vereins für Geldern und Umgebung, Geldern, 2001, , pp. 185–204. Richard Klapheck: Die Baukunst am Niederrhein. Vol. 1. Düsseldorf, 1915/1916, pp. 46–66 (online). Hanns Ott: Rheinische Wasserburgen. Geschichte – Formen – Funktionen. Weidlich, Wurzburg, 1984, , pp. 133–171. Castles by type