Irenaeus of Lyons, Against Heresies 3.3.3
Therefore the blessed Apostles, having founded and instructed the Church, handed over the episcopate of the Church to Linus. Paul mentions this Linus in his letters to Timothy (1 Timothy). Anacletus succeeded him, and after him, in the third place from the Apostles, Clement obtained the episcopate. Clement had seen the Apostles themselves and conversed with them; he still had the Apostles' preaching and tradition before his eyes, for many who had been taught by the Apostles were still surviving at that time. Under his leadership, therefore, when a significant dissension had arisen among the brothers at Corinth, the Church at Rome wrote a most powerful letter to the Corinthians. It summoned them to peace, restored their faith, and announced the tradition Clement had recently received from the Apostles. That tradition proclaims one God, almighty, the maker of heaven and earth, the shaper of man, who brought the flood, who called Abraham, who led the people out of the land of Egypt, who spoke with Moses, who established the law, who sent the prophets, and who prepared fire for the devil and his angels. This Father of our Lord Jesus Christ is proclaimed by the churches from Scripture itself; those who wish to learn can know it and understand the apostolic tradition of the Church. For this letter is older than those who now falsely teach and invent another God above the Demiurge and Maker of all these things. After Clement, Evaristus succeeded; after Evaristus, Alexander; and next, sixth from the Apostles, Sixtus was appointed. From him came Telesphorus, who also underwent a most glorious martyrdom; then Hyginus, then Pius, after whom came Anicetus. When Soter succeeded Anicetus, Eleutherius now holds the episcopate from the Apostles in the twelfth place. This order and succession demonstrate the tradition that comes from the Apostles in the Church and the proclamation of the truth. It is a most complete demonstration that has come down to us: the same life-giving faith which was in the Church from the Apostles until now has been preserved and handed down in truth.
Latin
Fundantes igitur et instruentes beati Apostoli Ecclesiam, Lino episcopatum administrande Ecclesiz tradiderunt. Hujus Lini Paulus in his que sunt ad Timotheum epistolis meminit. Succedit autem ei Anacletus: post eum tertio loco ab Apostolis episcopatum sortitur Clemens, qui et vidit ipsos Apostolos, et contulit cum eis, et cum adhuc insonantem preedicationem A postolorum et traditionem ante oculos haberet; non solus; adhuc enim multi supererant tune ab Apostolis docti.. Sub hoe igitur mente, dissensione non modica inter eos qui Corinthi essent fratres facta, scripsit quae est Romze Ecélesia potentissimas literas Corinthiis, ad pacem eos congregans, et reparans fidem eorum, et annuntians quam in recenti ab Apostolis acceperat traditionem, annuntiantem unum Deum omnipotentem, factorem cceli et terre, plasmatorem hominis, qui induxerit cataclysmum, et advocaverit Abraham, qui eduxerit populum de terra A®gypti, qui collocutus sit Moysi, qui legem disposuerit, et prophetas miserit, qui ignem preeparaverit diabolo et angelis ejus. Hune Patrem Domini nostri Jesu Christi ab ecclesiis annuntiari, ex ipsa scriptura, qui velint discere possunt, et apostolicam Ecclesize traditionem intelligere, cum sit vetustior epistola his qui nune falso docent, et alterum Deum super Demiurgum et factorem horum omnium que sunt commentiuntur, 8. Huie autem Clementi succedit Euaristus, et Euaristo Alexander, ac deinceps sextus ab Apostolis constitutus est Sixtus, et ab hoc Telesphorus, qui etiam gloriosissime martyrium fecit: ac deinceps Hyginus, post Pius, post quem Anicetus. Cum autem successisset Aniceto Soter, nunc duodecimo loco Episcopatum ab Apostolis habet Eleutherius. Hac ordinatione et successione ea quee est ab Apostolis in Ecclesia traditio et veritatis praeconatio Et est plenissima hee ostensio, unam et pervenit usque ad nos. eandem vivificatricem fidem esse, quae in Ecclesia ab Apostolis usque nunc sit conservata, et tradita in veritate> 4.