The church fathers are the ancient and influential Christian theologians and writers who developed the orthodoxy (right belief) of the faith. They are generally categorized as follows:

A. After (1) the Apostolic Fathers come in the second century (2) the Greek apologists, followed by (3) the Western apologists somewhat later, (4) the Gnostic and Marcionite heretics with their apocryphal Scriptures, and (5) the replies to them.

B. The third century gives us (1) the Alexandrian writers of the catechetical school, (2) the writers of Asia Minor and (3) Palestine, and the first Western writers, (4) at Rome, Hippolytus (in Greek), and Novatian, (5) the great African writers, and a few others.

C. The fourth century opens with (1) the apologetic and the historical works of Eusebius of Caesarea, with whom we may class St. Cyril of Jerusalem and St. Epiphanius, (2) the Alexandrian writers Athanasius, Didymus, and others, (3) the Cappadocians, (4) the Antiochenes, (5) the Syriac writers. In the West we have (6) the opponents of Arianism, (7) the Italians, including Jerome, (8) the Africans, and (9) the Spanish and Gallic writers.

D. The fifth century gives us (1) the Nestorian controversy, (2) the Eutychian controversy, including the Western St. Leo; (3) the historians. In the West (4) the school of Lérins, (5) the letters of the popes.

In this collected work the following volumes are presented under the editorship of Philip Schaff:

Volume I - The Apostolic Fathers with Justin Martyr and Irenaeus
Volume II - Fathers of the Second Century
Volume III - Latin Christianity: Its Founder, Tertullian
Volume IV - The Fathers of the Third Century
Volume V - The Fathers of the Third Century
Volume VI - The Fathers of the Third Century
Volume VII - The Fathers of the Third and Fourth Centuries
Volume VIII - The Fathers of the Third and Fourth Centuries
Volume IX - Recently Discovered Additions to Early Christian Literature; Commentaries of Origen

St. Augustine:

Volume I - St. Augustine's Life and Work, Confessions, Letters
Volume II - The City of God, Christian Doctrine
Volume III - On the Holy Trinity, Doctrinal and Moral Treatises
Volume IV - The Anti-Manichaean Writings, The Anti-Donatist Writings
Volume V - Anti-Pelagian Writings
Volume VI - Sermon on the Mount, Harmony of the Gospels, Homilies on the Gospels
Volume VII - Homilies on the Gospel of John, and the First Epistle of John, Soliloquies
Volume VIII - Expositions on the Psalms

St. Chrysostom Volumes

Volume IX - On the Priesthood, Ascetic Treatises, Select Homilies and Letters
Volume X - Homilies on the Gospel of St. Matthew
Volume XI - Homilies on the Acts of the Apostles and the Epistle to the Romans
Volume XII - Homilies on First and Second Corinthians
Volume XIII - Homilies on the Epistles to the Galatians, Ephesians, Philippians, Colossians, Thessalonians, Timothy, Titus, and Philemon
Volume XIV - Homilies on the Gospel of St. John and the Epistle to the Hebrews

Nicene and Post-Nicene Fathers

Volume I - Eusebius: Church History from A.D. 1-324, Life of Constantine the Great, Oration in Praise of Constantine
Volume II - Socrates: Church History from A.D. 305-438; Sozomenus: Church History from A.D. 323-425
Volume III - Theodoret, Jerome and Gennadius, Rufinus and Jerome
Volume IV - Athanasius: Select Writings and Letters
Volume V - Gregory of Nyssa: Dogmatic Treatises; Select Writings and Letters
Volume VI - Jerome: Letters and Select Works
Volume VII - Cyril of Jerusalem, Gregory Nazianzen
Volume VIII - Basil: Letters and Select Works
Volume IX - Hilary of Poitiers, John of Damascus
Volume X - Ambrose: Select Works and Letters
Volume XI - Sulpitius Severus, Vincent of Lerins, John Cassian
Volume XII - Leo the Great, Gregory the Great
Volume XIII - Gregory the Great II, Ephriam Syrus, Aphrahat
Volume XIV - The Seven Ecumenical Councils

All the works presented here are cross-linked to the Bible and have in-line footnotes linked to the back of the work.