The most important rivers are the Rhine (Rijn), the Waal, the IJssel and the Maas (border with North Brabant). The border with Flevoland is formed by the so-called randmeer ("border lake") of the Flevopolder.
In the 11th century, Guelders was a county. It was called Gelre in Dutch and Geldern in German. In 1339, it became a duchy. At first, it existed of the surroundings of the city of Geldern (now in Germany). By the end of the 14th century, it included most of the modern province of Gelderland and parts of the province of Limburg and of the German District of Cleves. It became part of the Habsburg Netherlands in 1543, one of the Seventeen Provinces.
At this moment (2005), these are the municipalities in Gelderland:
Aalten | Apeldoorn | Arnhem | Barneveld | Berkelland | Beuningen | Bronckhorst | Brummen | Buren | Culemborg | Doesburg | Doetinchem | Druten | Duiven | Ede | Elburg | Epe | Ermelo | Geldermalsen | Groenlo | Groesbeek | Harderwijk | Hattem | Heerde | Heumen | Lingewaal | Lingewaard | Lochem | Maasdriel | Millingen aan de Rijn | Montferland | Neder-Betuwe | Neerijnen | Nijkerk | Nijmegen | Nunspeet | Oldebroek | Oude IJsselstreek | Overbetuwe | Putten | Renkum | Rheden | Rijnwaarden | Rozendaal | Scherpenzeel | Tiel | Ubbergen | Voorst | Wageningen | West Maas en Waal | Westervoort | Wijchen | Winterswijk | Zaltbommel | Zevenaar | Zutphen