The Terminal Classic period (ca. AD 800–1000) in the Southern Maya Lowlands witnessed a precipitous decline in the erection of carved stone monuments, a decline that corresponds to shifts in political ideologies and the disappearance of many prominent royal dynasties. Although Southern Lowland sites are often considered peripheral to the events and innovations occurring elsewhere in Mesoamerica during this time, a recently discovered stela, Stela 29, at the site of Ucanal in Peten, Guatemala, underscores the active role of the site in broader political movements in the ninth century. Our iconographic, textual, and stylistic analysis of this stela, in concert with other Terminal Classic monuments from the site, reveals a vernacular cosmopolitan aesthetic whereby local Classic Maya styles were infused with images and elements that referenced connections with peoples from northern Yucatan, the Gulf Coast, and Central Mexico.