Without a doubt, the Frenchman Marc Bloch (1886-1944) is the father of modern historiography. His wise judgments synthesized them in an orbit that, in Spanish, appeared with the title of Introduction to History, actually Apologie pour l \ 'histoire ou Métier d \' historieu. Posthumous work published by his friend and collaborator Lucien Febvre, when his warlike vicissitudes caused him to be sacrificed in 1944, a victim of the racial condition of his ancestors. His work is an authentic journey through the twists and turns and obstacles encountered by the historian to unravel the secrets of this exciting human science, today and in times past.