An extended pursuit of a long-vanished edifice has led to the uncovering of an imperial cult temple’s foundations in central Italy, situated beneath what was formerly a grassy parking area.

This revelation, augmented by a contemporaneous Roman missive detailing the structure’s erection, implies that the Empire’s transition from pagan traditions to Christianity was neither abrupt nor seamless, but rather a gradual and somewhat complicated affair.

“We unearthed three walls of a substantial edifice that, based on available evidence, appears to have been a Roman temple dating to the era of Constantine,” states Douglas Boin, an archaeologist affiliated with Saint Louis University in Missouri.

Constantine, also recognized as Constantine the Great, holds the distinction of being the inaugural Roman emperor to embrace Christianity, approximately seven decades prior to its formal adoption as the Roman Empire’s state religion in 380 CE.

Preceding this significant cultural shift, societal norms dictated the veneration of a diverse pantheon of pagan deities. However, within the excavated remnants of this newly discovered subterranean temple, Boin and his associates believe they have identified indicators of a transitional phase, a period when individuals paid homage to an imperial cult under the auspices of a Christian sovereign, Constantine himself.

It is essential to distinguish this from contemporary interpretations of ‘cults’ found in communities today. In this historical context, ‘cult’ denotes religious observances where an emperor or a ruling family was revered as a demigod or a divine entity.

Given Constantine’s adherence to a monotheistic creed centered on a singular, omnipotent deity, his endorsement of such ancestral veneration presents a paradox that is as insightful as it is confounding.

“This finding illuminates the enduring connections between the classical pagan world and the nascent Christian Roman society, elements frequently obscured or omitted from overarching historical accounts,” explains Boin, who presented this discovery at the Archeological Institute of America’s annual gathering in January.

“While we were aware that pagans continued to worship in their temples during the fourth century, the artifacts from those sites were invariably small and of minor significance,” Boin elaborates.

“Furthermore, we knew that Christians supported the imperial cult, but lacked any concrete understanding of the physical locations where these practices occurred. This temple serves as a crucial link between those two historical observations.”

Commencing in 2021, Boin embarked on a collaborative effort with a cadre of Italian archaeologists, including Letizia Ceccarelli from the Polytechnic University of Milan. Their objective was to locate a temple referenced by Constantine in a fourth-century epistle addressed to the inhabitants of Spello, a town presently situated roughly 150 kilometers (just over 90 miles) north of modern-day Rome.

This correspondence, which came to light in the 18th century, contained directives from Constantine mandating the construction of an imperial cult temple in his honor. Nevertheless, the definitive whereabouts of this structure “had remained unconfirmed,” the researchers articulate in their conference paper.

Employing advanced remote-sensing technologies, such as magnetometry and ground-penetrating radar, the team meticulously surveyed the undulating terrain surrounding Spello, actively seeking buried architectural remnants that might correspond with Constantine’s temple.

Their investigations converged on the grounds of the Villa Fidelia, an estate dating from the Renaissance. Initial excavations at this site yielded the foundational elements of a large structure, presumed to be of Roman origin. The researchers characterize this discovery as a “monumental” archaeological find.

It remains uncertain, however, how the broader archaeological community will perceive these architectural remains and whether the assertions regarding the site’s historical significance will gain widespread acceptance, particularly as excavations are still ongoing and the team’s findings have not yet undergone formal peer review.

“We stand on the verge of presenting tangible evidence that will profoundly challenge the simplistic and orderly perceptions people hold regarding major epochs of societal transformation,” observes Boin.

“Periods of cultural evolution are rarely as sweeping as they appear when one is experiencing them firsthand. Considerable ambiguity exists at the intersection of individual customs, broader societal norms, and overarching culture.”

“Therefore, the prospect of this temple potentially having been dedicated to Constantine’s divine ancestors, serving as a focal point for imperial worship within an increasingly Christianized world of that era, is remarkably intriguing, and I am delighted that we can bring this to light.”