English summary: The monastery of Vatopedi was founded around 980 by a member of the Byzantine aristocracy, who, according to legend, was from Adrianople. The monastery quickly became one of the biggest of Mount Athos. Until the end of the 12th century, its history is poorly known, because, from this early period, only eleven documents are preserved. The archives of Vatopedi, however, are the richest of Mount Athos for the 13th-15th centuries. Many documents illustrate the connections between the monastery and the highest Byzantine aristocracy as well as the part the latter played in the aggrandizement of the monastery. This first volume of the Actes de Vatopedi touches on the legends pertaining to the foundation of the monastery and traces its history as well as that of its estates on Mount Athos, in Macedonia, Thrace and Lemnos island from the origins to 1329. A special study on the katholikon, including its architecture and decoration, also sheds light on the history of Vatopedi during this period. Then follow the description, analysis, commentary and edition of 69 documents, 43 of which were previously unpublished; an appendix presents the analysis of a Slavic document and the edition of two fakes. All of these documents are reproduced in an album comprising 88 phototypic plates. Among these documents, which are of very diverse types, it is worth mentioning especially the diataxis of Maximos, the founder of the monastery of Boreine near Philadelphia, as well as several wills and a series of deeds of lease pertaining to vine planting near Thessalonike. French description: Le monastere de Vatopedi a ete fonde aux alentours de 980 par un membre de l'aristocratie byzantine, qui, selon la legende, etait originaire d'Andrinople. Tres vite, le monastere devint l'un des plus importants de l'Athos. Son histoire jusqu'a la fin du XIIe siecle est mal connue, car, pour cette epoque ancienne, onze actes seulement sont conserves. En revanche, les archives de Vatopedi sont les plus riches de l'Athos pour les XIIIe-XVe siecles. De nombreux actes montrent les liens entre le monastere et la plus haute aristocratie byzantine, et le role qu'elle a tenu dans l'enrichissement du monastere. Ce premier volume des Actes de Vatopedi evoque les legendes relatives a la fondation du monastere, retrace son histoire et celle de son domaine foncier a l'Athos, en Macedoine, en Thrace et a Lemnos, des origines a 1329. Une etude particuliere sur le katholikon, architecture et decor, eclaire aussi l'histoire de Vatopedi a cette epoque. Viennent ensuite la description, l'analyse, le commentaire et l'edition de 68 actes, dont 43 etaient jusqu'ici inedits, puis, en appendice, l'analyse d'un acte slave et l'edition de deux faux. Tous les documents sont reproduits dans un album de 88 planches phototypiques. Parmi les actes, qui sont de types tres varies, on peut mentionner la diataxis de Maxime, fondateur du monastere de Boreine pres de Philadelphie, plusieurs testaments et une serie d'actes de bail relatifs a la plantation de vignes pres de Thessalonique.