Frontier Colonization or Abandonment
The establishment of ancient imperial frontiers was also accompanied by marked settlement shifts to accommodate the state requirements. Often, ancient empires promoted frontier population aggregation with colonies of soldiers, administrators, or craft producers (Drummond and Nelson 1994; Eadie 1977; Lewis 1977, 1984; Smith 1991; Steffen 1980). Regardless of their origins, these colonies were more likely to participate in the state economy and therefore become progressively assimilated (Eadie 1977; Cooter 1977). In ancient Rome, the frontier facilities encouraged the establishment of new villages, mobile camps, and broad market areas. Beyond the frontier, adjacent Germanic tribes also settled along the frontier gates and trading stations to have privileged access to Roman goods (Drummond and Nelson 1994). It is also likely that some empires organized the massive mobilization of frontier colonies, rather than constituting a civilian effort.
The Inka are well known for the movement of sizable mitmaqkuna colonies for state economic, political, and defensive purposes (Patterson 1992; Rostworowski 1988; Rowe 1946, 1982). In Incallajta, an Inka center in the Southern Andes, the Chui and Cota were brought as soldiers, whereas the state farms in the adjacent Cochabamba valley were attended by 14,000 colonists of diverse origins (Patterson 1992; Wachtel 1982:201). Likewise, in the Inka border of Tucuman in what is presently Argentina, the Chicha became privileged mitmaqkuna frontier soldiers (del Rio and Presta 1995; Espinoza Soriano 2006 ; Williams et al. 2009).
More hostile frontiers could also encourage depopulation and the formation of buffer zones as protective shields (Cooter 1977; DeBoer 1981; Myers 1976; Parker 1998; Prescott 1965; Upham 1986). Typically, buffer zones were in ecologically marginal areas like deserts or impassable mountains, and were inhabited by small populations (Parker 1998:382; Prescott 1965). In situations of rivalry between neighboring empires like Assyria and Urartu, smaller polities acted as effective buffers (Parker 1998:393).