The Mapuche are a group of indigenous inhabitants of south-central Chile and southwestern Argentina, including parts of present-day Patagonia. The collective term refers to a wide-ranging ethnicity composed of various groups who shared a common social, religious and economic structure, as well as a common linguistic heritage as Mapudungun speakers. Their influence once extended from the Aconcagua River to the Chiloé Archipelago and spread later eastward to the Argentine pampa.