Local Expertise and Architectural Innovation in the Earth-Built Theaters of Roman Gaul (20 min)

Presenters

John Sigmier, University of Pennsylvania

Abstract

This paper examines how indigenous construction expertise drove the development of architectural regionalism in the theater buildings of Rome’s northwestern provinces in the first two centuries C.E. Northwestern theaters departed from the standard western Mediterranean model in several ways, among which was the use of earthwork substructures rather than masonry vaults to support audience seating. Scholars have historically treated this as an act of architectural simplification, motivated by costs of materials and a lack of technical expertise at provincial construction sites. I argue instead that earthworks were a sophisticated structural solution that continued an established local tradition of monumental construction.

In this analysis, I focus on the caveas at Argentomagus, Ricciacus, and Alesia, three representative examples of Gallo-Roman theaters whose seats were arrayed on artificial embankments. To understand the specialized knowledge and labor needed to raise and maintain large earthwork caveas, I take a geoarchaeological approach, comparing the theaters to earth-built mounds in pre-Columbian North America. I then examine Iron Age ramparts in Gaul as a second comparative dataset, situating the theaters within a tradition of monumental Gallic earthen architecture that persisted into the first decades of Roman imperial control.

This analysis makes clear that earthwork construction at the scale of the theaters required both a sophisticated understanding of soil hydrology and engineering and the preferential sourcing of specialized building materials. I argue that Gallic builders chose earthworks over masonry because the necessary structural and material expertise was readily available in Roman Gaul, where the active tradition of large-scale earth construction proved easily adaptable for theater building. These conclusions call for a new understanding of earthwork caveas in the Roman northwest not as evidence of the limitations of provincial builders, but rather as monuments to the innovative deployment of local architectural knowledge and skill.