This is the first in a two-volume critical investigation of one of the earliest and most important of the New Testament Apocrypha, the Protevangelium of James (also known as the Infancy Gospel of James). Zervos challenges the prevailing view that the ProtJas is a second century unitary document, and finds instead that it is a product of an ongoing redactional process by which a first century CE 'heretical' text was progressively conformed to the 'orthodox' Christian doctrine of the time. Zervos tells the story of how an early apocryphal gospel provided the developing church with doctrinal material that was incorporated into both the theology and the ecclesiastical liturgical cycle of the medieval Church, and became a significant part of the standard catechism for generations of Christians. Volume I contains the Greek text, English translation, and a critical introduction. For the first time the readings of the vast majority of the known Greek manuscripts will appear together with a transcription of the original text of the complete copy of the ProtJas found in Papyrus Bodmer V.