A new spirit.--The age of wanton bloodshed, too, had largely passed. The New Laws, promulgated in 1543, stood for a new spirit, and royal authority had by now become somewhat established on the frontiers. In proportion as the _encomenderos_ were discredited for their abuses and as their power over the Indians was checked, a larger and larger place was found on the frontier for the missionaries, to whom passed much of the actual work of subduing and controlling the natives.
Audiencia and diocese of Nueva Galicia.--In 1544 Compostela became the seat of the new diocese of Nueva Galicia. Four years later the new Audiencia of Nueva Galicia was established there. About 1550 Guadalajara became the seat of both jurisdictions, and the judicial and ecclesiastical capital of all the country to the north and northeast, a position which it long occupied. The Audiencia district was subdivided into _corregimientos_, each under an alcalde, subject to the Audiencia. Within the _corregimientos_ were Indian _partidos_, each under a native alcalde, subject to the encomenderos or the missionaries.
The Zacatecas mines.--In spite of the check caused by the Mixton War, northward expansion in Mexico was soon stimulated by the discovery of rich mines, and by the ambitions of the new viceroy. Mines developed in southern Nueva Galicia were soon eclipsed by those of Zacatecas, which were opened in 1548 by Juan de Tolosa, Cristóbal de Oñate, Diego de Ibarra, and Baltasar Treviño. These men soon became the richest in America, and Zacatecas the first mining town in New Spain. The fame of the "diggins" spread, and other parts of the country were for a time nearly depopulated by the rush of miners.
Francisco de Ibarra.--Inspired by the "boom" at Zacatecas, the Audiencia of Nueva Galicia planned to subdue the districts of Sinaloa and Durango. Ginés Vázquez de Mercado, sent for this purpose in 1552, wasted his energies in a fruitless search for a fabled mountain of pure silver, and was defeated by the Indians near Sombrerete. Martin Pérez, sent by the Audiencia to the same district in 1558, came into conflict with Francisco de Ibarra, agent of the viceroy. In 1554 Ibarra began a series of explorations by means of which, in the course of eight years, he and his men opened in northern Zacatecas the mines of San Martin, San Lucas, Sombrerete, Chalchuites, Aviño, Fresnillo, and other places. To make these expeditions, he equipped himself at his own or his uncle's expense with soldiers, horses, Negro slaves, Indian servants, and droves of stock for food. He attracted miners and settlers by furnishing them with outfits and by giving them free use of mineral deposits.