This research aims to analyze for the first time the history of the Coronel-Lota mining basin, prior to the arrival of the first miners in the 19th century. The study focuses on three main axes: the impact on the indigenous communities, the Spanish military presence and the expansion of the first rural haciendas. First, it investigates the distribution and organization ofMapuche communities in the area before and during the colonial encomienda system, which changed with the settlement of the "Indian friends". The second axis deals with the role of the Spanish army and the construction of the forts of San Pedro and Colcura. Finally, the third axis analyzes the creation of rural haciendas in the 17th century, which produced food for the soldiers and the indigenous communities. The research uses sources from the National Historical Archive of Chile and the General Archive of the Indies, as well as colonial chronicles and academic studies. Each of the axes is developed as an independent investigation, with records that include documents on encomiendas, censuses and military registrations, allowing us to understand how these factors contributed to the formation of the coal mining community in the region. This approach seeks to integrate pre-industrial history into the narrative of the industrial heritage of the coal basin.