Gelderland, Guelderland (both: gĕlˈdərlənd) [key], or Guelders gĕlˈdərz, province (1994 pop. 1,851,400), c.1,940 sq mi (5,000 sq km), E central Netherlands. It borders on Germany in the east. Arnhem, the capital, as well as Nijmegen and Apeldoorn are the chief cities. Largely an agricultural region, it is drained by the IJssel River and by the Lower Rhine and Waal rivers, which enclose the Betuwe, a fertile agricultural lowland in the southwest. The Veluwe, west of the IJssel, is an uncultivated, hilly heathland that is popular as a resort area. The region is also used as a military headquarters. The duchy of Gelderland was conquered (1473) by Charles the Bold of Burgundy, after whose death (1477) it regained its independence. It passed to the House of Hapsburg in 1543 and joined (1579) the Union of Utrecht of the Netherlands against Spain. Part of Gelderland, including Geldern, the ducal capital, was ceded (1715) by the Netherlands to Prussia.