The Duchy of Gelderland was a historical region in the eastern part of the present-day Netherlands. It emerged in the late Middle Ages and became an important political entity, known for its strategic location along trade routes and its rich agricultural land. The duchy was ruled by various noble families, including the House of Egmond and the House of Orange-Nassau. In the 16th century, Gelderland became a contested area during the Eighty Years' War as it was sought after by both the Spanish and the Dutch. Eventually, it was incorporated into the Dutch Republic in the late 16th century, marking the decline of its independence and influence in the region.