I will review in this seminar this historical evolution of the concept of"Dark Matter", from the first observations of "anomalies" in the 30's until the development of the hypothesis of the existence of a dark halo. The presentation will be entirely based on the original historical authors, reconstructing (by their ideas but also their mistakes) the appearance of a dark side of the Universe. The talk will include discussions of original articles by Poincaré, Zwicky, Oort, Jansky, Gamow, Peebles, Zeldovich, Bond and many others, opening on the prospect for the near future.