Servius Tullius
"Mons Caelius" would have been included in the city perimeter under the reign of Ancus Marcius. The list of "Septimontium" mentions it, and it was part of the 1st city quarter ("Suburana") in the division made by Servius Tullius. In the later Augustan division, it became the "Regio II Caelimontium".