Dynamics of the Ancient Inka Imperial Frontiers
This brief comparison of four Inka frontier segments suggests that their varied nature responded to different political, economic, and ecological conditions. In regions like northern Ecuador, the Inka state established tight defensive perimeters to optimize the protection of valued exchange networks while minimizing inner rebellion. In the southeastern frontier segment in the region that is today Argentina, the borders were formed by strongholds positioned on strategic interfaces and were designed to protect valuable trading corridors that penetrated deep into the jungle. In comparison, on the southernmost frontier edge in Araucanian territory, the fortified political frontier was surpassed by a broader economic zone that facilitated the extraction of foreign resources, along with the selective incorporation of outer groups. Changing political conditions, distinct available resources, and the diverse indigenous reactions were all central in shaping the dynamics of the frontier segments.
Notwithstanding the differences, some commonalities become apparent. Inka frontier fortifications were often placed in important corridors of communication, trade, and strategic interfaces. Depending on the importance of the trading networks or the intensity of threat posed by the native populations, these fortifications formed tight defensive cordons or were intentionally more spaced out. Hence, the Inka frontier installations were not large fortifications with substantial standing armies; instead, they were often small. Most likely, they were occupied by limited contingents of military mitmaqkunas and trusted local allies, and backed up by supernumerary frontier forces ready to be mobilized whenever needed. Furthermore, some of these frontier installations had multifunctional
roles, serving for diplomacy, for political incorporation, and even as advance outposts. As part of these efforts, a road network linked the frontier facilities to ease trade or to mobilize the imperial troops. Some of these strongholds were also situated in ecological and cultural interfaces to optimize access to desirable resources. This comparison also shows the varying degrees of state control, different levels of participation of state representatives in the regional economies, and the role that native frontier allies had in the frontier tasks. Therefore, in a spectrum of possibilities, the Inka established frontiers that ranged from relatively open to more militarized perimeters depending on a set of factors like geography, specific economic interests, and shifting political circumstances. Other aspects that remain to be understood in greater detail are the changing state policies regarding the frontier regions and the role that the central government and competing elite factions had in the imperial expansion.
Ancient imperial frontiers were unique settings for studying the interplay between people, their institutions, and their environment. Despite the similarities, each Inka frontier region faced unique challenges where the state institutions were constantly challenged, tested, and modified. As a result, indigenous communities played a critical role in the state frontier politics as valuable allies, rivals, and invaders, and as providers or consumers of goods and resources flowing across the frontiers. Far from being simple divisive lines, the Inka frontier zones became the nexus for complex socioeconomic processes varying in scope, magnitude, and extension. In the case of the Southeastern Inka frontier, this research has provided an opportunity to study the fascinating encounter between the Inka, one of the most powerful and successful pre-Columbian polities, and a set of extremely belligerent tropical tribes that the Inka were seemingly unsuccessful to subdue. Hopefully, future research in other Inka frontier segments will contribute to refine our understanding of this empire, as experienced by the myriad of populations dwelling on the borders.