Only the tituli were allowed to distribute sacraments. The most important priest in a titulus was given the name of Cardinal. Pope Marcellus I (at the beginning of the 4th century) confirmed that the tituli were the only centres of administration in the Church. In 499 a.d., a synod held by Pope Symmachus listed all the presbyters participating, as well as the tituli who were present at that time.:
This is a list of churches of Rome cited in Wikipedia articles or with related files on Wikicommons. The churches are grouped according to the time of their initial construction: the dates are those of the first record of each church. The reader, however, should not expect the current fabric of the buildings to reflect that age, since over the centuries most have undergone reconstruction. Almost all the churches will thus appear considerably more recent, and as a patchwork of periods and styles.
^Some scholars have identified the 3rd Century hall beneath the church as a meeting room for a Christian community. Others do not agree with this view, claiming there are no proofs of Christian use before the 6th Century. Krautheimer, p. 115.
Krautheimer, R., Corpus Basilicarum Christianarum Romae, vol. 3.