Skip to Content

Battle at Los Batanes? Rescue Excavations at a Fortified Tiwanaku Colony in Sama, Peru

Sarah Baitzel, Washington University in St. Louis, Project Grant 2018–2019


Many Pre-Columbian states used warfare to expand territories and subjugate neighboring populations (Arkush et al. 2005; Webster 2000). Tiwanaku (AD 500–1100), a pristine Andean highland state (3800 masl), did not. Tiwanaku’s expansion across the south-central Andes relied on non-violent trade relations and demographic colonization. Tiwanaku founded sprawling, multigenerational colonies in temperate lowland valleys that offered desirable agricultural resources (Goldstein 2005). The absence of defensive architecture, weapons, and skeletal trauma at Tiwanaku colonies in the Moquegua valley points to non-confrontational strategies that contrast with other expansive states in the Andes (Quilter 2002; Schreiber 1987). The disintegration of the Tiwanaku state beginning in the 11th century A.D., however, initiated a political and social fragmentation that led to regional conflict and ethnogenesis. This process finds expression in the foundation of new defensive settlements and the emergence of diverse new practices and styles that derived from a shared Tiwanaku origin (Sharratt 2011).

This project examines the intersection between state expansion and collapse, violence, and vertical exchange in the southern Andes from the perspective of the Los Batanes site, a recently discovered fortified Terminal Middle Horizon settlement in the middle Sama valley, southern Peru. Investigations of households, burials, and defensive architecture shed light on the continuity of vertical exchange networks, and the proliferation of local practices in a time of regional sociopolitical change.


Los Batanes

The archaeological site of Los Batanes is in the middle Sama valley (500 masl) in the far south of coastal Peru. Perched above the valley bottom on the right river margin, the site covers an area of 15 ha and is enclosed by a perimeter wall on three sides and the bluff edge on the fourth. The site was reported during regional archaeological survey in 2017. Surface finds of Tiwanaku style ceramic sherds, camelid bone and marine shell suggested a highland-affiliated population that participated in a wide-ranging exchange or mobility networks. While groundstone artifacts suggest an emphasis on agricultural activities at the site, projectile points found in and around the site point to acts of defense or aggression on the part or against the site’s residents. In light of the preliminary evidence and the broader regional context, our project sought to answer the following questions:

  1. In what subsistence strategies and exchange networks did the residents of Los Batanes participate? What was their cultural affiliation and how does it reflect on their relation to other highland and local communities in the region?
  2. How did violence shape the lives of Los Batanes residents? Are there indicators such as skeletal trauma or raiding to suggest direct acts of aggression that warranted the construction of a defensive perimeter wall and the production and habitual use of projectile points?

In addition, installations of municipal water and roads in early 2018 posed an imminent threat to parts of the site creating the need for rapid archaeological intervention and measures to protect Los Batanes.


Results of the 2018 Season

Our excavations at Los Batanes in Summer 2018 included seven units in the center and the along the perimeter wall of Los Batanes covering a total area of 76 m2.


Cultural Affiliation, Domestic Architecture, and Burial Practice

Permanent architecture at Los Batanes is dominated by agglutinated circular structures adjoining walled-in plazas. Buildings had double-faced walls made from locally available gypsum and caliche filled with ashy sediments and domestic refuse. Plazas contained the foundations of ephemeral orthogonal structures superimposed by burials that attest to a final use of communal spaces as cemeteries. The co-occurrence of different architectural traditions points to functional, ethnic, or temporal divisions of occupation at Los Batanes.

We recovered a small number of Tiwanaku-style sherds among an overwhelmingly Cabuza-style assemblage causing us to reconsider previous models of the site’s chronology and cultural affiliations. Rather than aligning temporally with the Tiwanaku expansion to the north of Sama, Los Batanes was likely founded during the second half of the Middle Horizon and occupied into the early Late Intermediate Period. The cultural affiliation of the residents of Los Batanes with the Cabuza style found in the coastal valleys of Ilo to the north and Azapa to the south is further manifested in the grave goods found with nine burials. Cabuza-style black-on-red decorated keros, tazones, and pitchers accompanied the remains of men, women, and children interred in subterranean pits sealed with wooden beams and stone covers. The textiles used for wrapping the dead were decorated with bichrome supplementary warps.


Subsistence and Mobility

The population of Los Batanes relied on agropastoralist subsistence. Faunal remains from domestic assemblages consisted over 90% of camelid remains from adult and juvenile individuals. Predominance of axial skeletal elements over limb bones in the assemblage suggests specialized processing or consumption in some areas of the site. Marine shells and fish bones comprised a significantly smaller portion of the faunal assemblage but were equally ubiquitous. Macrobotanical remains of maize, and chili peppers attest to the cultivation and consumption of crops that continue to dominate local agriculture today. Flotation revealed the presence of quinoa, a high-elevation crop that would have been introduced by highlanders and may have been grown locally.

The Pacific coast is over 30 miles to the west of Los Batanes, yet marine resources (likely extending to seaweed, salt, and perhaps guano) were desired and consumed by the site’s residents. On the contrary, reliance on camelids for fiber and meat points to exchange and mobility with highland regions. Pasture in this arid zone is restricted to the valley bottom, most of which is dedicated to agricultural use, and to seasonal lomas on the desert plains surrounding Los Batanes. The large amount of camelid remains at Los Batanes supposes an extensive presence of animals at the site. It is possible that the large perimeter wall around the site served seasonally as an enclosure to house highland herds.


Fortification and Violence

Excavations at the southern end of the perimeter wall at Los Batanes revealed the remains of a 1-meter wide bulwark of low height in an advanced state of collapse. A single or double course of large rocks on either side of the wall protected a core made from cobble stones and gypsum cemented with caliche and superimposed with refuse fill. The wall was constructed on top of a natural gypsum surface. On its northern side (i.e., site interior) a slightly raised, prepared floor abutted the base of the wall. Openings in the perimeter wall along the western and northern end of the site suggest access points, although recent construction and motor vehicle traffic have compromised the integrity of the wall architecture.

Preliminary analysis of human remains from burials near the wall and in the site interior have not revealed any skeletal trauma indicative of interpersonal violence, although the possibility of lethal soft-tissue injuries cannot be ruled out. Projectile points made from white chert, many of which were found outside the settlement, were also recovered from midden deposits and plaza surfaces in the site center. The prevalence of projectile points in and beyond household spaces at Los Batanes suggests that their distribution and use was pervasive. Whether these objects are tied to hunting or defensive activities (or both) remains to be determined as recovery and analysis of human and faunal remains at the site continues.


Summary and Conclusion

The results of our excavations at Los Batanes were instrumental for reshaping our understanding of the occupation of the site in regard to broader cultural dynamics that occurred in the region during the Middle Horizon–Late Intermediate transition. Our first season of excavation at Los Batanes failed to identify other lines of evidence to elucidate how violence may have affected the population directly, although the presence of projectile points is confirmed as pervasive in all contexts of the site. Burial practices and ceramic assemblages at Los Batanes form a close match with that Cabuza culture of the Azapa and Ilo valleys, suggesting that the site was established concomitant with the onset of sociopolitical crisis in the Tiwanaku realm. The site’s population was engaged in highland-coastal exchange that supplied camelids, highland crops and marine resources in return for local cultivates such as maize and chili peppers. In light of the agropastoralist practices, it is possible that the perimeter wall may have served as a defensive bulwark but also as an enclosure for herds that seasonally moved through the valley for pasture and caravan transport. Owing to the support from the Dumbarton Oaks Project Grant we are currently cooperating with the Ministerio de Cultural DDC Tacna to implement necessary protective measures at the local and administrative levels to protect the site from encroaching threats of agricultural and infrastructural development.