This article aims to trace nidol-lonko (great cacique) Juan Lorenzo Kolupi, from his appearance in military records during the Guerra a Muerte (1819) until his death in 1850. The underlying objective is to understand the operation of Mapuche politics during the first half of the nineteenth century, starting from an analysis of his particular characteristics and those he shared with his peers. Focusing on important events he experienced, we realized that his power was built in a war-like scenario that linked the Mapuche society's internal conflicts with Spanish-Chilean military divisions. In this context, Kolupi's actions were effective and valid. However, these properties weakened during his last years, to the point where he became an inconvenient actor for much of the present concerns at the border.