Previously... is a section in the Wing Commander 4 Guide which fills in the backstory from the previous games. This is one of the sources that ties Christopher Blair in WC1 events in a more 'direct' way (though other sources may or may not contradict it (in particular history added by the Movies and related novels), see canon for more details). This summary is also of note is that it also covers the events of many of the novels as well that were part of the canon at the time of its release. This and a "Biography" in Wing Commander Prophecy Guide are as close to a "Christopher Blair' biography (but not memoirs) that have been published, although these sources do not focus on Blair at all times (nor are they 100% comprehensive).