Throughout Roman history, members of the imperial family featured regularly in central coinage, on reliefs and statues, and in inscriptions – both in Rome and the provinces. Roman emperorship was a de facto dynastic system, which explains the sustained emphasis on imperial fathers, mothers, wives and children. Only very rarely was lineage wholly ignored. This posed major problems for imperial representation under the so-called Tetrachy; an explicitly non-dynastic imperial system, not organised by bloodline but governed through collegiate rule. How could such ‘corporate government’ present itself in a society that was used to dynastic terminology when indicating predecessors and intended successors? This article explores some of the alternative modes through which tetrarchic representation aimed to present non-dynastic rule, and shows how these alternatives proved ultimately unsuccessful. Apparently, the constraints of tradition in imperial imagery were too stringent to overcome.

Modern scholarship, following the template laid down by Lactantius and Eusebius, has viewed the achievements of Constantine chiefly through the prism of his Christianity, with the result that his secular achievements have been comparatively neglected. This article addresses those secular policies, focusing on how Constantine sought to assert his legitimacy during the various stages of his rise to power. It takes as its starting point the modern debate on the legitimacy of Constantine’s elevation to the purple and whether or not he can be justifiably described as a usurper. Through close scrutiny of a variety of documentary sources—particularly inscriptions, but also coins—it establishes how Constantine sought to affirm the legitimacy of his position as emperor at a number of critical moments, and to have that legitimacy accepted both by other members of the imperial college and by the empire’s populace at large. It emerges that Constantine appealed to a variety of means to assert his legitimacy, for example, as a member of a college of emperors, as the preferred candidate of the army or Senate, as victor in civil war, or as a member of a dynasty. Furthermore, he invested considerable effort in buttressing his claims by actively deconstructing the legitimacy of his rivals, notably Maxentius and Licinius, whom he designated instead as tyranni. Thus Constantine made a notable contribution to the articulation of ideas of imperial legitimacy in the fourth century, and his strategies were adopted, most immediately, by his sons.

The figure of Maxentius emerged through interesting circumstances during the Late Tetrarchy, and his status as ‘usurper’ of the title of emperor was criticized and despised by the other leaders, namely the Augustus Galerius. Rome’s Praetorian Guard brought Maxentius into power from imposed retirement primarily to become the conservator urbis suae, which was further emphasized by his coinage and architecture. But Maxentius remained a usurper, as his position was not officially recognized, and he instead sought to legitimize his reign through political propaganda, and through an elaborate building program he instituted in Rome. This program was situated mainly at the eastern end of the Forum Romanum, and was marked most prominently with the Basilica of Maxentius. The massive Basilica was combined with the newly constructed Temple of Romulus and the refurbished Temple of Venus and Roma to create a ‘Forum of Maxentius’ in the pattern of prior emperors Augustus, Vespasian, and Trajan. The Basilica solidified the presence of Maxentius in this section of the Forum, a fact reiterated by the existence of a Republican-era tie to the Velian Hill that it punctuates. I contend that the Basilica’s placement and spatial referencing attempt to change the political and architectural topography of the most visible area of Rome, and that its distinctive construction and material technique was used to enhance and reinforce the status of its creator, thereby legitimizing Maxentius’ status as Rome’s true Emperor. This thesis combines the elements outlined above to create a picture of Maxentius’ hopes for a new and more powerful Rome. I investigate the ability of Maxentius’ program to influence the power of his illegitimate reign in Rome, and how he used allusions to previous Roman monuments to increase their validity, including the basilica building type, and its new attachment of bathhouse concrete vaulting technologies.