The war was long and hard, and the Carlist forces (labeled "the Basque army" by John F. Bacon) achieved important victories in the north under the direction of the brilliant general Tomás de Zumalacárregui. The Basque commander swore an oath to uphold home rule in Navarre ("fueros"), subsequently being proclaimed commander in chief of Navarre. The Basque regional governments of Biscay, Álava, and Gipuzkoa followed suit by pledging obedience to Zumalacárregui. He took to the bush in the Amescoas (to become the Carlist headquarters, next to Estella-Lizarra), there making himself strong and avoiding the harassment of the Spanish forces loyal to Maria Christina (Isabella II). 3,000 volunteers with no resources came to swell his forces.