In Potosin, in present-day Bolivia, war broke out between Basques and twins, when Basque Juan Urbieta was killed. The following day, the Basques took to the streets to avenge the murder. Bikuinak was the informal name of Spaniards living in the region. The cause of the war was the desire to control the silver mines of Cerro Rico. Thanks to the American conquest, the economic and political hegemony of this Bolivian area was in the hands of some Basques, within the Spanish imperialist project.