Investigations at Xunantunich indicate that this major Belize River Valley site rose rapidly to regional prominence during the Late Classic Hats' Chaak phase (a.d. 670–780). While the social, political, and economic reasons for Xunantunich's relatively late and rapid rise are still not fully understood, it has been suggested that this ascent was a direct result of either a patron-client relationship with, or owing to direct control by, the larger primary center of Naranjo in neighboring Guatemala. In this paper, we evaluate previous arguments for this proposed dynamic relationship between the two sites, and we discuss the political implications of more recently acquired data in our assessment of this relationship.