The Inka Frontier in Southern Chile
A third frontier segment of singular interest is located in the southernmost edge of the empire (currently Chile). During the reigns of Tupac Inka Yupanqui and Huayna Capac, the Inka expanded beyond the modern city of Santiago in central Chile (Figure 8.4) (Lizarraga 1968; Santoro and Munoz 1995; Schiappacasse and Niemeyer 2002; Silva 1992-1993; Uribe 1999-2000). Similar to other frontier expanses, the Inka targeted productive agricultural and mineral production pockets. This was the case of the valleys in Santiago and Aconcagua populated by the hostile Pro- maucae and Aconcagua, both rich in copper and gold sources (Planella et al. 1991; Rossen et al. 2010; Stehberg L. 1976). Near Santiago, the Inka established important mines and founded the administrative center of Mopocho, which congregated a dense population engaged in a range of agrarian tasks (Stehberg L. 1976). Therefore, it is not surprising to find that Santiago was vigilantly protected. To the north of Santiago, in the Aconcagua Valley, there were the Inka fortifications of Cerro Mercachas, Cerro de la Cruz, and Cerro Mauco; to the south, in the Maipo Valley, were the strongholds of Chena, Chada, and Cerro del Inga along the political frontier. All of these fortifications were positioned adjacent to the Inka road, and some were staffed with Inka-Diaguita allies (Dillehay and Gordon 1988; Rossen et al. 2010).
Farther south, a smaller group of fortifications were constructed between the Maule and Bio Bio Rivers. They delineated the outer economic frontier in the form of advance points (Figure 8.4). These installations were charged with defending the region against the invading Araucanos (Raffino and Stehberg 1999). Nevertheless, there is evidence of some successful advances. The establishment of exchange circuits in foreign territory facilitated the export of prestige Inka materials, technology, and even imperial institutions (Dillehay and Gordon 1988). For example, in the cemetery of Cocule in the more distant Valdivia region, some Araucano individuals used Inka ceramics and metal tupu ornaments to advertise their status (Dillehay and Gordon 1988:152).
Although this region did not face outer tropical populations as occurred with other eastern frontier segments, it experienced similar processes. As in the Southeastern Inka frontier, indigenous populations played a critical role in defending the territory against external invasions. Also, in both frontier segments the Inka constructed fortified segments
Figure 8.4. Location of main Inka sites in the Southern Inka frontier, in today’s Chile. The map also shows the distribution of the main ethnic groups in the region. Map based on D’Altroy 2002; Dillehay and Gordon 1988; Rossen et al. 2010; Stehberg L. 1976.
in strategic areas to protect valuable economic pockets. Nevertheless, they diverged in terms of population settlement within the frontier zone. As previously noted, Oroncota was a small administrative center, whereas Mopocho had a large population. In light of the concerted efforts to protect Mopocho through several fortified segments, this provincial center resembles more the installation of Quito in the northern frontier. Furthermore, the Inka in the Araucanian territory were seemingly more successful in encouraging trade and acculturation beyond the frontier than they did in Cuzcotuyo. Perhaps this responded to the endemic conflict prompted by the Guarani-Chiriguano advances.