Promaucae, also spelled asPromaucas orPurumaucas (fromQuechuapurum awqa: wild enemy), were an Indigenous pre-ColumbianMapuche tribal group that lived in the present territory ofChile, south of theMaipo River basin ofSantiago, Chile and theItata River. Those to the north were calledQuillotanes[1] andMapochoes by the Spanish colonists). They spokeMapudungun, like theMoluche to the south, and were part of thePicunche tribe that lived north of theItata River.

TheInca referred to all the peoples who were not under their empire aspuruma auca. Because these Picunche tribes were successful in defending their territory against theInca Empire in theBattle of the Maule, they were given this distinctive name. In an effort to transliterate the word into Spanish phonetics, the Spanish referred to them as thePurumaucas orPromaucaes. The early Spanish in the area knew their region as the province of Promaucae and its inhabitants were calledPromaucaes.
The Promaucae are the first inhabitants of theRancagua Valley of whom there is a historical account. TheMapuche included them in the group that they knew as thepicunche, "people of the north". The Promaucae, as has already been mentioned, constituted a distinct cultural unit separate from those Picunche who lived to the north of theMaipo, namedmapochoes, and to the south of theMaule, designatedmaules andcauquenes. The Inca invaders noted the great military capacity and will to fight of the Promucae.
They were farmers and constructed some earthworks for irrigation. They left ceramic vestiges.
The Inca in their expansion used thePucara del Cerro La Muralla, which they strengthened. The Pucará was the southernmost Inca settlement then known. Inca expeditions in this territory were organized byTúpac Inca Yupanqui at the end of the 15th century and later byHuayna Cápac.
The history of this period is based on what was written in later chronicles. These chronicles indicate that the Promaucaes, informed about the coming of the Incas, allied themselves with the Antalli, Pincu and Cauqui subgroups, forming an army of 20,000 men. The Incas sent emissaries to persuade the locals into accepting Túpac Inca Yupanqui as sovereign, but the Purumaucas decided to face the Inca forces in the so-calledBattle of the Maule.[2] During the confrontation, both sides suffered many fatalities and neither army won a clear advantage.
On the fourth day, neither side left their own camp, both of which had been fortified, as they hoped to defend them if their opponents attacked. The fifth and sixth days were passed in the same manner but by the seventh, the Purumauca and their allies retired and returned home claiming victory. The Inca later considered chasing them, on which some chiefs agreed; but they decided to secure only what they had already conquered, with whichTúpac Inca Yupanqui agreed.
Due to their proximity to theInca Empire, the Promaucae learned the new technology that the Inca displayed in their new domains.
Among the peoples the Spanish called the Promaucae, adopting the term from the Inca, were particularly the people of theRapel River valley.[3] Those of theMataquito River valley were called theCure, for which the province ofCurico is named.[3] The people in theMaule River valley and to the south were distinguished asMaule. Those to the south of the Maule and north of the Itata River were known asCauqui by the Inca[4] orCauquene.[3] The Spanish named theCauquenes River after them.