In the beginning, Chrestians (as they were called for decades before the name “Christians” for them became standardized) used the same Scriptures as their Judaic antecessors, at least their Judaic antecessors known as the Hellenistai, i.e. Hellenistic Jews. In other words, they used the Greek-language Septuagint. Most of the works in the current New Testament were recognized with varying levels of acceptance across the Mediterranean and Southwest Asia.
The Septuagint, 3rd century BCE
Since the Vulgate re-ordered the books within its Old Testament, the order they fell in the Septuagint follow here:
Genesis, Exodus, Leviticus, Numbers, Deuteronomy, Joshua, Judges, Ruth, 1 Kings1, 2 Kings2, 3 Kings3, 4 Kings4, 1 Chronicles, 2 Chronicles, 1 Esdras, 2 Esdras5, Esther6, Tobit, Judith, 1 Maccabees, 2 Maccabees, 3 Maccabees, 4 Maccabees, Psalms7, Prayer of Manasseh, Job, Proverbs, Ecclesiastes, Song of Songs, Wisdom of Solomon, Sirach, Psalms of Solomon, Twelve Minor Prophets8, Isaiah, Jeremiah, Baruch, Lamentations, Letter of Jeremiah, Ezekiel, Daniel9
1 1 Samuel
2 2 Samuel
3 1 Kings
4 2 Kings
6 with additions
7 including Psalm 151
8 Hosea, Amos, Micah, Joel, Obadiah, Jonah, Nahum, Habakkuk, Zephaniah, Haggai, Zechariah, Malachi
9 with additions
The oldest copies of the Septuagint bore the Tetragrammaton in Hebrew script in those places in which it occurred in the Hebrew.
In addition to the above, many apocryphal “Old Testament” works are quoted or otherwise referenced in the New Testament and should get at least an honorable mention:
1 Enoch, Odes of Solomon, Assumption of Moses, Martyrdom and Ascension of Isaiah, Testament of Abraham, Testament of the Twelve Patriarchs, Jubilees
The earliest mention of anything approaching a scriptural canon appeared in the first half of the second century.
Doctrina duodecim Apostolorum, 2nd century CE
This church order, a generation or so after the Didache, recommends that only the Old Testament, the Prophets, the Gospels, and the Acts of the Apostles be read in church.
Marcion of Sinope, 138 CE
Marcion was founder of a heterodox sect named for him that was quasi-Gnostic. He appeared in Rome in 138, bringing with him two volumes. First was the Evangelikon, also known as the ‘Gospel of the Lord’, an early version of the later Gospel of Luke missing several later interpolations. He also brought the Apostolikon, a compilation of letters attributed to Paul of Tarsus: Galatians, 1 Corinthians, 2 Corinthians, Romans, 1 Thessalonians, 2 Thessalonians, Ephesians, Colossians, Philemon, Philippians, Laodiceans, and Alexandrians
Justin Martyr, mid-2nd century CE
In the First Apology and Dialogue with Trypho, Justin discusses several “memoirs of the apostles” which clues reveal to be all the Synoptics, and possibly the Gospel of John as well.
Elsewhere he quotes or refers to Romans, 1 Corinthians, Galatians, Ephesians, Colossians, Philippians, Titus, and 1 Timothy.
Tatian, 165 CE
He and the Encratites, and their daughter sects (Severians, Aquarii, Apotactites), accepted the Torah, the Prophets, and the Gospels, but rejected Acts and the Pauline Epistles.
Regarding the gospels, he composed what may be the first gospel harmony, called the Diatesseron. This composite work compiled all material of the four canonical gospels except the two genealogies in Matthew and Luke and the Pericope Adulterae in John, which lends support for their later composition. It also included material from several noncanonical gospels.
The Diatesseron remained the official gospel of the Aramaic-speaking churches through the sixth century.
Muratorian Canon, 170 CE
This fragment of parchment list as canonical all the works of the canonical NT, save 3 John, plus the Apocalypse of Peter, the Wisdom of Solomon. It recommends that The Shepherd of Hermas, brother of Pope Pius, be read privately but not in church.
Peshitta, c. 180
Its Old Testament had been translated into Aramaic from Hebrew in Edessa in the early first century CE. The translators included all the canonical books in Hebrew, and later Christians may have included many of the apocryphal books as well. The New Testament included the Diatesseron (which was accepted by all Aramaic-speakers), Acts, and the Pauline Epistles, but excluded the Catholic Epistles and the Apocalypse of John.
Clement of Alexandria, c. 200
Used all 27 canonical works, plus the Epistle of Barnabas, 1 Clement, Apocalypse of Peter, the Shepherd, Gospel of the Hebrews, Gospel of the Egyptians, Preaching of Peter, Traditions of Matthathias, Sibylline Oracles, and the Oral Gospel.
Origen, first half of the second century
Accepted all four gospels but rejected the letters of Paul
In his History of the Christian Church, Eusebius divides the works of the New Testament into the following three categories:
Canonical: Four gospels, Acts, Pauline epistles (including Hebrews), 1 John, 1 Peter
Antilegomena: 2 John, 3 John, 2 Peter, James, Jude
Deuterocanonical: Acts of Paul, The Shepherd, Apocalypse of Peter, Epistle of Barnabas, Didache, Apocalypse of John
Claronmontanus Canon, c. 350
This codex’s New Testament lacked Philippians, 1 Thessalonians, 2 Thessalonians, and Hebrews, but in their place included 3 Corinthians, Acts of Paul, Apocalypse of Peter, Epistle of Barnabas, The Shepherd.
Council of Laodicea, 364
The clerics approved of all the current New Testament save the Apocalypse of John.
Athanasius, Easter message 367
The bishop lists all the books of the current canon.
Apostolic Canons, 380
This church order published approximately this year adds Jubilees to the Old Testament, and 1 Clement, 2 Clement, and the Apostolic Constitutions to the New Testament
Vulgate Bible, 383
Commissioned by Pope Damasus I, and translated by Jerome, this translation into the lingua franca of the western empire more or less fixed the canon in the West, at least implicitly.
Synod of Hippo, 393
Presided over by Augustine of Hippo, this synod explicitly fixed the canonical works of the New Testament by decree, and also made canonical the fiction that Paul wrote the Epistle to the Hebrews. These decisions were reaffirmed at the synods of Carthage in 397 and 419.
Ecclesiastical Canons of the Holy Apostles, 6th century
All books of the canonical New Testament save the Apocalypse of John, but including 1 Clement, 2 Clement, and the Apostolic Constitutions
Harklean version of the Peshitta, 616
This edition of the Aramaic scriptures marks the first inclusion of five books—2 Peter, 2 John, 3 John, Jude, Apocalypse of John—which had previously been excluded.
Armenian canon, 1200
Until this year, the canonical books among Armenian Christians included all books of the New Testament except for the Apocalypse of John. Armenians sometimes still include 3 Corinthians in their canon, and the Testaments of the Twelve Patriarchs in their Old Testament.
The New Testament includes the twenty-seven books of the universal canon, plus 1 Clement and 2 Clement.
The Ethiopian canon of the Tanakh, or Old Testament, includes the books of the Septuagint, though in different order, with Jubilees and I Enoch added to it; its broader canon includes the Book of Josephus son of Ben Garon, also known as Pseudo-Josephus.
The Ethiopian New Testament includes the twenty-seven universally recognized books plus the broader canon made up of the Book of the Covenant, in two parts; the Sinodos, a compilation of ancient church orders which includes the Apostolic Church Order, the Apostolic Tradition, and the Apostolic Constitutions, along with additional material, the whole being ascribe to Clement of Rome; the Book of Clement, in seven parts, a uniquely Ethiopian work; and the Ethiopian Didascalia, much different than the better known Didascalia Apostolorum, but similar to Books I-VII of the Apostolic Constitutions.