Coordinates: 51°47′N 6°8′E / 51.783°N 6.133°E / 51.783; 6.133
The Duchy of Cleves (German: Herzogtum Kleve; Dutch: Hertogdom Kleef) was a State of the Holy Roman Empire emerged from the mediaeval Duisburggau. It was situated in the northern Rhineland on both sides of the Lower Rhine, around its capital Cleves and the towns of Wesel, Kalkar, Xanten, Emmerich, Rees and Duisburg bordering the lands of the Prince-Bishopric of Münster in the east and the Duchy of Brabant in the west. Its history is closely related to that of its southern neighbours: the Duchies of Jülich and Berg, as well as Guelders and the Westphalian county of Mark. The Duchy was archaically known as Cleveland in English.
The duchy's territory roughly covered the present-day German districts of Cleves (northern part), Wesel and the city of Duisburg, as well as adjacent parts of the Limburg, North Brabant and Gelderland provinces in the Netherlands.
In the early 11th century Emperor Henry II entrusted the administration of the Klever Reichswald, a large forested area around the Kaiserpfalz at Nijmegen directly subordinate to the Imperial rule, to local Lower Lorrainian nobles at Geldern and Kleve. A County of Cleves (German: Grafschaft Kleve; Dutch: Graafschap Kleef) was first mentioned in the 11th century. In 1417, the county became a duchy. Upon the death of Count Johann in 1368, the fief was inherited by his nephew Adolf III of the Marck. Cleves and the Marck were finally ruled in personal union by the House of La Marck after Adolf's elder brother Count Engelbert III had died without issue in 1391. King Sigismund of Germany raised Count Adolph I to the status of a duke and a Prince of the Holy Roman Empire in 1417.