Nueva Vizcaya was the first province of northern Mexico to be explored and settled by the Spanish. Sometimes called the kingdom of Nueva Vizcaya, it served as the "heartland" of the northern frontier for some 250 years. In the early years of settlement the name referred to the area north of Zacatecas. The province eventually included most of the modern Mexican states of Chihuahua and Durango, and, at different times, parts of Sinaloa, Sonora, and Coahuila. The area was initially explored by Nuño de Guzmán in 1531, José de Angulo in 1533, and Ginés Vázquez de Mercado in 1552. Francisco de Ibarra explored the region in 1554, and mining and missionary activities commenced soon thereafter. In 1562 Ibarra was appointed to colonize the region, then regarded as the northernmost part of the province of Nueva Galicia. Ibarra began to establish settlements and organized the region as Nueva Vizcaya, named for his home province of Vizcaya, Spain. The capital of the province, Durango, was similarly named for Ibarra's birthplace. Over the course of the next 250 years, exploratory expeditions and missionary efforts launched from Nueva Vizcaya settled New Mexico, founded Parras and Saltillo, and helped to develop Sonora and Sinaloa. Nueva Vizcaya remained a separate province after the Mexican War of Independence but was divided into the states of Chihuahua and Durango in 1824.