English summary: A kind of intellectual lethargy takes hold of us whenever we discuss the Northern Hemisphere, which we never fail to relegate to some impregnably inaccessible corner of our minds. Yet, it is an integral part of our Western civilization - insofar that Iceland has produced a cultural phenomenon so remarkable that specialists (at a loss to find a satisfactory "explanation") refer to it as the "Icelandic Miracle." Indeed, the fact that a handful of men and women, who settled on this island at the end of the 9thcentury to create a peerless society - well ahead of its time - complete with very sophisticated laws and jurisprudence, and, above all, a literature comprising some of the most exquisite works of our Middle Ages (much more than mere sagas) - should suffice to convince us of how urgent it is for us to know more about Iceland. Such is the purpose of this book, in which the author strives to reveal as much about Iceland as he demythologizes. This is only natural, since it was no other than this culture and this civilization that laid the foundations for the prestigious phenomenon of the Vikings. Regis Boyer is a professor of Scandinavian languages, literatures and civilizations at the Universite de Paris-Sorbonne, where he is the Director of the Institute of Scandinavian Studies. He has authored some twenty reference works and numerous translations. His other works published by Belles Lettres are : La Mort chez les anciens Scandinaves (1994), Deux Sagas islandaises (1996), Les Sagas legendaires (1998) et Les Sagas miniatures (1999). French description: Une sorte de paresse intellectuelle s'empare de nous des qu'il s'agit du Nord, que nous nous empressons de releguer dans des brumes inexpugnables. Pourtant, il appartient au premier chef a notre civilisation occidentale et aura meme suscite, avec l'Islande, un phenomene culturel d'une telle qualite que les specialistes, en mal d'"explication" satisfaisante parlent de "miracle islandais".En effet, que la poignee d'hommes et de femmes qui se sont installes dans cette ile a partir de la fin du IXe siecle pour y edifier une societe sans equivalent ailleurs- et notoirement en avance sur son temps-, une legislation, une jurisprudence qui confondent l'entendement, et surtout une litterature qui compte parmi les plus beaux fleurons de notre Moyen Age (car elle va bien au dela des sagas), voila qui devrait suffire a nous convaincre de l'urgence de combler nos lacunes sur ce point: c'est ce a quoi s'emploie le present volume, qui s'attache autant a divulguer qu'a demythifier. Car apres tout, ce sont bien cette culture et cette civilisation-la qui auront sous-tendu le prestigieux phenomene viking.