The city of Albano, located at the fifteenth milestone from Rome on the Via Appia Antiqua, and two miles from the ancient Alba Longa.

[3] According to the Liber Pontificalis[4] the Emperor Constantine I provided the city with a new basilica, that of Saint John the Baptist: He also presented the church with various vessels of silver and silver gilt, and endowed the church with a number of local properties, including the farm of Mola (a mile west of the town), possession of the lake of Albano, the Massa Mucii, all the abandoned houses in Albano, possession of gardens, and other properties.

[5] This Constantinian basilica was destroyed by fire toward the end of the 8th century, or at the beginning of the 9th, along with the bishop's residence.

[6] Ferdinando Franconi has established[7] the identity of this basilica with the present Albano Cathedral, which still contains some remains of the edifice dedicated by Pope Leo III to Saint Pancras.

The importance of this early Christian community is apparent from its cemetery, discovered in 1720 by Giovanni Marangoni.

martyrum quae sunt foris civitatis Romae, is considered by Giovanni Battista de Rossi[citation needed] as the synopsis of an ancient description of the cemeteries, written before the end of the 6th century: Saint Senator of Albano[11] is inserted in the martyrology for 26 September (et in Albano Senatoris), without further specification.

It included ten castelli: Sabello, Riccia, Genzano, Cività-Lavinia, Nemi, Marino, Castelgandolfo, Pratica, Ardea, and Nettuno.

[15] By the beginning of the 20th century, it had become apparent to the papacy that the suburbicarian bishops had become overburdened with the responsibilities of their curial and diocesan duties.

The decree also ordered that the bishop of Ostia, when promoted to that position, should also retain his previous bishopric; the diocese of Velitrae was to be removed from his jurisdiction, and from that point the suburbicarin bishops would be: Ostiensis, Portuensis et Sanctae Rufinae, Albanensis, Praenestina, Sabinensis, Tusculana, Veliterna.