County of Vexin: Map & History

History

The name Vexin is derived from a name for a Gaulish tribe now known as the Veliocasses. They had inhabited the area and made Rouen their most important city.

Vexin was divided into two parts—the French Vexin in the east and the Norman Vexin in the west—under the Treaty of Saint-Clair-sur-Epte on 11 July 911. King Charles the Simple ceded to the Norman leader Rollo the territory between the Epte in the north, the Avre in the south, and the sea, laying the groundwork for the future Duchy of Normandy, which included part of Vexin, while the remainder stayed under the French king's control.

In 1031, Duke Robert I of Normandy aided King Henry I against a revolt led by the dowager queen, Constance of Arles, and was rewarded with the French Vexin between the Epte and Oise, including Pontoise.

Economy and regional natural park

Most rural communes of the French Vexin united in 1995 to form the French Vexin Regional Natural Park, headquartered in Théméricourt. It includes 94 communes (77 in Val-d’Oise and 17 in Yvelines) plus six gateway towns, covering 680 square kilometres (260 sq mi) with 79,000 inhabitants.

The Picardy communes in the Oise remained outside the park, as managing a park across two regions (Île-de-France and Picardy) seemed too complex at the time (despite precedents like the Normandy-Maine Regional Natural Park, established in 1975). In Val-d’Oise, two communes (Ambleville and La Chapelle-en-Vexin) initially declined to join but did so in 2008, alongside three Yvelines communes (Évecquemont, Vaux-sur-Seine, and Juziers).

Geography

Today, the county's territory is shared by parts of five departments of France: Val-d'Oise and Yvelines in the Île-de-France region; Oise in the Hauts-de-France region; and Eure and Seine-Maritime in the Normandy region. The major towns are Pontoise, Vernon, Meulan-en-Yvelines, Gisors, and Les Andelys. The plateau is primarily an agricultural region with some manufacturing located in the valleys.

to the north by the valleys of the Esches, the Troesne, or simply by the cuesta of Vexin.

In the Oise, the boundaries of the French Vexin are theoretically marked by the cuesta of Vexin, separating the Vexin plateau from the neighboring Pays de Thelle plateau.