What & Who Determined Scripture to be Scripture

I believe it's critically important we understand the process and events in which Biblical canon historically, archaeologically, theologically, as well as spiritually, was formed. Because it was this process that determined the current doctrinal structures and what is considered scripture and what is not. It is important to understand the formation of doctrine and the canonization process, how, when, where, why it happened and who was involved in the process and what was going on at the time, that may have influenced the outcome.