Zacatecas, including craftsmen, merchants, clerics and adventurers. In 1550, royalty found its way to Zacatecas in the person of Leonor Cort�s Moctezuma, the illegitimate daughter of conquistador Hernan Cort�s and Isabel Moctezuma, daughter of the Aztec emperor. Do�a Leonor married Juan de Tolosa. The settlement grew over the space of a few years into one of the most important cities in New Spain and the most populous after Mexico City. The camp became a parish in 1550, in 1585, the it was declared a city with the name of "Muy Noble y Leal Ciudad de Nuestra Se�ora de Zacatecas" (Very Noble and Loyal City of Nuestra Se�ora de Zacatecas), receiving its coat of arms from Philip II of Spain at the same time. The success of the mines led to the arrival of indigenous people and the importation of black slaves to work in them. The mining camp spread southwards along the course of the Arroyo de la Plata, which now lies underneath Manuel Hidalgo Avenue, the city's main road. Tall buildings where constructed along here due to the lack of flat area on which to build. The first house was supposedly built in 1547, just before the fortress and metal foundry. Hospitals and hospices were built in the 1550s.
Zacatecas is one of the most rich states in Mexico. One of the most important mines from the colonial period is the El Eden mine. It began operations in 1586 in the Cerro de la Bufa. It principally produced gold and silver with most of it production occurring in the 17th and 18th centuries. Today, the opening of this mine is within the city limits and was closed to mining in 1960. It was reopened as a tourist attraction in 1975. By the end of the 16th century, the city was the second most important, after Mexico City, and the income its mines produced for the Spanish Crown made it one of the most powerful in Europe. Its importance was not only due to mining. Most of the monastic orders in New Spain eventually established monasteries, making Zacatecas an important center
