Santiago del Estero (Spanish pronunciation: [sanˈtjaɣo ðel esˈteɾo]), also called "Santiago", is a province in the north of Argentina. Neighbouring provinces, clockwise from the north, are Salta, Chaco, Santa Fe, Córdoba, Catamarca and Tucumán.

The autochthonous inhabitants of these lands were the Juríes-Tonocotés, Sanavirones and other tribes. Intriguingly, Santiago del Estero is still home to about 100,000 speakers of the local variety of Quechua, making this the southernmost outpost of the language of the Incas. Quite when the language reached the area, and how, remains unclear—it may even have arrived only with the native troops that accompanied the first Spanish expeditions.

Diego de Rojas first reached this land in 1542. Francisco de Aguirre founded Santiago del Estero in 1553 as the northernmost city founded by Spanish conquistadores coming from the Pacific Ocean.

Santiago then passed under different governments, from the intendency of Tucumán to the Audiencia de Charcas, then again to Tucumán, of which it was later to be designated capital.

However, the bishop moved to Córdoba in 1699 and the government moved to Salta two years later. Furthermore, the silver route between Buenos Aires and the Viceroyalty of Peru passed through Tucumán rather than through Santiago. The combination of these circumstances drastically reduced the importance of the city and the territory and, by the beginning of the 19th century, the city had barely 5,000 inhabitants.

...
Wikipedia