The 100: A Ranking of the Most Influential Persons in History is a 1978 book by Michael H. Hart, an astrophysicist, alien life researcher and white separatist.Published by his father's publishing house, it was his first book and was reprinted in 1992 with revisions. It is a ranking of the 100 people who, according to Hart, most influenced human history.Unlike various other rankings at the time, Hart explicitly wasn't attempting to rank on "greatness" as a criterion, but rather how the course of human history most changed due to the actions of that person.