Gustav II Adolf's daring gamble in landing at Usedom in 1630 drew attention to the vast Duchy of Pomerania. The Duchy's relevance for seventeenth-century history exceeded its importance as a theater of war, and French historical studies are unfortunately lacking in this area. This introduction sets out its geographical framework: large grain fields estates and a very long coastline whose ports are the sites of Pomerania's main cities. The article reviews, after the extinction of the Griffon dynasty in 1637, the political evolution of this disputed Baltic land, between Sweden and the Holy Empire and in contact with Brandenburg, Poland, and Denmark. Finally, it reflects upon the specificities of this area, both Germanic and Slavic, culturally and religiously united.