Basque nationalism is a movement with roots in the Carlism an the loss, by the laws of 1839 and 1876, of the Ancien Régime relationship between the Basque provinces and the crown of Spain. The Spanish government revoked part of the fueros after the Third Carlist War. The fueros were charters granted by the successive kings of Castile and acted as part of the Basque legal system dealing with matters regarding the political ties of the Basque Provinces with the crown. The Fueros gave Basque subjects a privileged position in Spain with special tax and political status; basically, Basques were not subject to direct levee to the Castilian army, although many volunteered, especially in the Spanish navy, which was led, among others, by Basque sailors like Juan Sebastián Elcano.