In the mid-19th century, the diocese of Albano contained only about 8,000 persons. It included ten
castelli: Sabello, Riccia, Genzano, Cività-Lavinia, Nemi, Marino, Castelgandolfo, Pratica, Ardea, and Nettuno. At the end of the century, it contained about 44,000 inhabitants, served by 60 secular priests and 124 priests of religious orders, and there were twelve parishes. The diocese had 67 churches, chapels, or oratories. There were three collegiate churches, with colleges of Canons, at Ariccia, Civita-Lavinia, and Nemi. 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 increase in commerce, in roads and travel, and the migration of people to the city, as well as the increased burden of duties in the papal administration because of the mass and complexity of problems affecting the Church, made some sort of relief necessary. On his own initiative, therefore,
Pope Pius X issued a decree,
Apostolicae Romanorum Pontificium, granting the bishops of Ostia, Porto, Albano, Palestrina, and Frascati each a suffragan bishop to carry the burden of their pastoral duties in their dioceses. The pope appointed the suffragans, who had full powers inside the diocese, subject to the cardinal's approval, but not the power to ordain or consecrate, or the right to have a throne or display their coat-of-arms. Further details were added by
Pope John XXIII in his apostolic letter,
Suburbicariis sedibus, defining the suffragan bishop as "Episcopus Ordinarius", with the same powers as other residential bishops, and enumerating the privileges of the cardinal bishop. In 1914, Pius X took steps to regulate the irregularities in the incomes of the six cardinal suburbicarian bishops. On his own initiative, after consulting with the curial cardinals and with their agreement, he issued the decree
Edita a Nobis, in which he ordered that in the future the incomes of the cardinal bishops should be placed in a single fund, administered by the Office of Economic Affairs, to which each cardinal must render an annual account. Each year, after 6,000 Lire was to be given to each suffragan bishop, the remaining money collected was to be divided into equal portions, the bishop of Ostia to receive two portions, and each of the other bishops one portion. 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 suburbicarian sees would be: Ostiensis, Portuensis et Sanctae Rufinae, Albanensis, Praenestina, Sabinensis, Tusculana, Veliterna. ==List of bishops==