The people of the western Basque provinces (ambiguously called "Biscay" up to that point) and Navarre sided with Carlos because ideologically Carlos was close to them and more importantly because he was willing to uphold Basque institutions and laws. Some historians claim that the Carlist cause in the Basque Country was a pro-"fueros" cause, but others (Stanley G. Payne) contend that no connection to the emergence of Basque nationalism can be postulated. Many supporters of the Carlists cause believed a traditionalist rule would better respect the ancient region specific institutions and laws established under historical rights. Navarre and the rest of the Basque provinces held their customs on the Ebro river. Trade had been strong with France (especially in Navarre) and overseas up to the Peninsular War (up to 1813), but getting sluggish thereafter.