Caesar and the pomerium of Rome

This study examines Julius Caesar’s plans for the expansion and redefinition of the pomerium, Rome’s juridical-sacral boundary. The analysis examines Caesar’s ambitious lex de Urbe augenda, which included engineering proposals such as the diversion of the Tiber to create new urban land and mitigate flooding. These projects were not only technical, but also had profound religious and legal implications, reflecting Caesar’s role as pontifex maximus and his vision for the urban development of Rome. The paper situates Caesar’s expansion of the Pomerium within the broader context of Republican and Imperial changes to the city’s boundaries. It highlights the unique challenges Caesar faced, including the need to balance urban growth, civic functionality and the symbolic elements of Rome’s spatial and political identity. His plans aimed to assert his legacy as the founder of a renewed Rome, rivalling figures such as Sulla and Pompey, while also addressing the practical needs of urbanisation and flood control. By reconstructing the hypothetical trajectory of the enlarged Pomerium, the study shows how Caesar’s vision influenced later imperial projects and the long-term evolution of Rome’s topography. The work highlights the importance of Caesar’s urban policy as a blend of innovation, political strategy and monumental ambition.