The Vexin (vɛksɛ̃) is a historical county of northwestern France. It covers a verdant plateau on the right bank (north) of the Seine comprising an area east-to-west between Pontoise and Romilly-sur-Andelle (about 20 km before Rouen), and north-to-south between Auneuil and the Seine near Vernon. The plateau is crossed by the Epte and the Andelle...