While The Bible contains the tenets of Christianity and all of the important teachings of the faith, it is impossible for a student of theology to truly understand Christianity without studying it in historical context. There are many important events in the history of Christianity that are not reflected in The Bible, and studying the cultures that first embraced Christ, as well as the historic transformations and conflicts that came long after The Bible was written, are crucial for anyone hoping to grasp the current state of Christianity These sites offer historical perspectives on many of the major events in the development of Christianity, from the Ancient Near East to the crusades, schisms, and religious conflicts, as well as different interpretations of the historic significance of certain bible passages. This isn’t a ranking of these sites, but an attempt to recommend resources on a broad swath of important historic happenings in Christianity. -from their blog http://theologydegreesonline.com/christian-history/