A short history of the codex and why it was so important to the development and spread of Christianity. Portions of this outline were presented in an informal “Message for All Ages” at ARK Community Church in Dalton, MA; Feb 1, 2016.
Prior to the first century CE (or so), nearly all written documents were in the form of single sheets or scrolls.
Because of the difficulty of unrolling scrolls to find particular passages and then having to roll them up again, longer books were often broken up into multiple scrolls. You can see this even today in the segmentation of 1 & 2 Kings and 1 & 2 Chronicles in the Hebrew Scriptures, both of which were originally single continuous texts.
And, because of the difficulty of managing and storing scrolls, very short books were often collated together into a single scroll. For instance, the 12 minor Hebrew prophets (Hosea, Joel, Amos, Job, Malachi, etc.), were often kept together in one or two scrolls.
The word “Codex” is from the Latin word for “wood” or “block” and is the technical term for a folio of pages stitched together. In other words, a book. The codex was developed by the Romans shortly before the time of Christ, Julius Ceasar may have been the first prominent Roman to use them.