Abstract
In this article we present a synthetic overview and preliminary analysis of the data collected by members of the Sierra del Lacandón Regional Archaeology Project (SLRAP) during four field seasons of research from 2003 to 2007. We examine the growth, development, and transformation of the Classic Maya polities of Piedras Negras, Guatemala, and Yaxchilan, Mexico, located in the Middle Usumacinta Basin. This analysis uses a conjunctive approach, incorporating analyses of iconography, epigraphy, settlement patterns, ceramics, mortuary patterns, and architectural styles. During the Late Preclassic period (c. 250 B.C.-A.D. 350) settlement was scattered widely across the study region and Piedras Negras and Yaxchilan were only two of a number of other equally powerful Preclassic communities. In the Early Classic period (c. A.D. 350-600) royal dynasties were established at both Piedras Negras and Yaxchilan and the population of the region became concentrated at these two sites. During the Late Classic period (c. A.D. 600-810) the political frontier between Piedras Negras and Yaxchilan was repopulated and transformed into a contested border zone surrounding a political boundary. This territorial expansion culminated in endemic warfare by the eighth century A.D., which may have ultimately led to the demise of these two Maya polities.