This article s both a study of the French-writing Spaniard Jorge Semprún's multilingual trajectory and a sociological analysis of the translational aspects of the Formentor prize, which he received in 1963 for his novel Le Grand Voyage. Created by Carlos Barral in the Majorcan peninsula of the same name and sponsored by several leading publishers (Seix-Barral, Einaudi, Galliimard, Weidenfeld & Nicholson, Rowohlt), the Formentor would become one of the major publishing initiatives in 1960s Europe, leaving its mark on a decade of avant-garde writing and opening up the literary border of Franco's Spain in the process. When awarded the Formentor, writers saw their work immediately translated in some ten languages (often by renowned translators) and distributed almost simultaneously in more than a doze, countries. A closer examination of the translation traffic generated by Semprún's Grand Voyage serves to illustrate the legitimizing force of a to this day unique initiative in the European annals of literary translation.