IN NO OTHER CITY OF THE EMPIRE DID THE IDEA OF ROMAN GOVERNMENT survive as tenaciously as in Rome itself. Two symbolic aspects sustained this idea: the concept of imperium, the privilege of continuing Roman imperial rule; and the counterpoint of populism, the trappings of a people's government, the Roman Comune, as contained in the rubric Senatus Populusque Romanus, or SPQR, stamped to this day on every length of pipe and sewer tube laid by the municipality. The Palatine was the physical location for the institutionalization of the concept of imperium during the Christian Middle Ages, and the Capitoline became the new home of the Roman Senate in the eighth century.

Of all the features that characterized Rome as the quintessential imperial city of classical antiquity, the Palatine was preeminent; it served as residence of the court and headquarters of the large and mighty imperial bureaucracy. If the imperial domain was readily transferable to the Church (as we have seen with large land grants), this was not the case for the Palatine, which as official residence of the emperor was managed by the Senate, as were the other major monuments of the ancient city. The Palatine was the symbol of imperial authority, the memoria of imperium, as it were, and was certainly not conveyable without admitting that the West was lost to the Byzantine Crown. Whether or not the Roman emperor, resident in Constantinople, ever saw the Palatine, it remained his premier palace up to the collapse of the Byzantine Exarchate in 752, when all pretense of holding the West ended.

Under the emperor Justin I (518–527), an office was created of three curatores carrying the highest title of illustris, who took charge of all imperial residences, including the Palatine. Later the office was decentralized and the number of curatores increased so that every palace had its own maintenance endowment and probably its own curator. A letter of Gregory the Great attests to the existence of “diverse Palatine officials in Rome.” The palace was functional at least until the early eighth century. The emperor Constans II stayed at the palace in 663 and it remained functional until at least 712, when the dux Christophorus resided there.