This thesis explores the persistence of muralism as a medium for political power. It considers the ambivalent role assumed by both the government-sanctioned and constituent-protest muralist in the span between medieval and contemporary wall painting. In Section 1, my theory establishes the medium’s intrinsic properties of political monumentality: its democracy of display, participatory experience, and dynamic tensions across space, time, and content. These aspects provide a framework for analyzing in Sections 2 and 3, respectively, Ambrogio Lorenzetti’s medieval fresco cycle in the Sienese Palazzo Pubblico and Banksy’s contemporary stencil motifs on the streets of London. Ultimately, the seemingly disparate examples within the case study offer insight on similar strategies of constructive visual power despite their significant temporal, technical, and stylistic differences, a testament to the enduring power of wall painting in politics.