Roman Catholic Diocese of Anagni-Alatri

The Italian Catholic Diocese of Anagni-Alatri , in Lazio, has existed since 1986. In that year the Diocese of Alatri was united to the historical Diocese of Anagni. The diocese is a suffragan of the Diocese of Rome.
Despite the usual claims of foundation in the apostolic age, there is no evidence of Christianity in Anagni until the 4th century, and, as a bishopric, the diocese first appears in history in the fifth century. Felix, Bishop of Anagni, was present at the Lateran Synod of Pope Felix III held in 487.

Wikipedia