om all) of these are "Gnostic" writings (stemming from various Gnostic sects), which were rejected because they were considered theologically inadequate or objectionable by the dominant strands of early Christianity; other writings were judged theologically acceptable, but were not accepted into the NT Canon because they were not judged to be "apostolic" (not stemming from the first generation of apostles, thus not old enough). See the Non-Canonical Literature page for comprehensive lists and full texts.
Nag Hammadi Library - A collection of fifty-two texts (forty-five separate titles, with some duplicates) bound in thirteen papyrus codies from the fourth century; discovered in 1945 in Upper Egypt, near the town of Nag Hammadi. Many but not all of these texts, which are written in Coptic (an Egyptian-Greek hybrid language of the early Christian era), are "gnostic," including several of the apocyphal texts mentioned above and several texts that were previously unknown. See the Nag Hammadi Library page for more details.
Patristic Literature - Writings of the "fathers" (bishops, theologians, and other influential leaders) of the early Church, again comprising a variety of genres: letters & epistles, homilies & sermons, theological and philosophical treatises, biblical commentaries, etc. These writings are often subdivided into two main groups: Ante-Nicene Literature (from before the Council of Nicea, 325 CE) and Nicene & Post-Nicene Literature (from after 325). See the Early Church Fathers page for full texts.
Documents of the Ecumenical Councils - Brief summaries of Christian beliefs (called "Creeds") and other decrees were agreed upon at meetings of the leading bishops of the early Church, esp. during the 4th and 5th Centuries, but continuing throughout the centuries. The first four Ecumenical Councils were held at Nicea (325), Constantinople (381), Ephesus (431), and Chalcedon (451).
Translations and Editions of the Bible:
Itala, or Old Latin - Christians in the Western Roman Empire (Italy & environs) began translating the Christian scriptures (both OT & NT) into their own native language, Latin, during the 3rd and 4th centuries. The OT books were usually translated from the LXX (the Greek translation and expansion of the HB - see above), while the NT books were translated from the original Greek texts.
Vulgate - a Latin version of both the Old and New Testaments, translated in the late 4th and early 5th centuries by St. Jerome at the request of Pope Damasus; it became the "official" Latin version of the Catholic Church for many centuries (i.e., the one used for the readings proclaimed during the Mass, as found in the official "Lectionaries"), intended to replace the various different "Old Latin" versions. As a true biblical scholar, Jerome was familiar not only with the Old Latin and the Greek versions of the New Testament, but also with the Old Latin, Greek (LXX) and Hebrew (HB) versions of the Old Testament. While comparing all these versions, Jerome based his own new Latin translation on the original language of each book, as far as possible. Thus, he translated the books of the HB from Hebrew into Latin, the deuterocanonical books (the extra OT books found in the LXX but not in the HB) from Greek into Latin, and the NT books from Greek into Latin.
Medieval Translations - Since the Vulgate was the dominant edition of the Christian Bible in the West from the 5th century onward, the earliest translations of the Bible into Anglo-Saxon, German, English, and other European languages were all translations of the Latin Vulgate, rather than being produced from the original languages (Hebrew, Aramaic, or Greek for the various books of the OT; Greek for the books of the NT). In other words, they were translations of translations!
Modern Translations - From the time of the Reformation onward (16th century), scholars have stressed the need to translate each biblical book from its original language, as far as possible. That is, rather than translating the book of Isaiah from its version in the Latin Vulgate or the Greek Septuagin