Around 1820, several manuscripts went missing from the archives of Maine-et-Loire in Angers, among them two of the region's most valued cartularies, Le Livre Noir de Saint-Florent, prés Saumur and La Grande Pancarte de Fontevrauld. These volumes were later discovered to have been purchased by the famed book collector Thomas Phillipps, and, in 1850, the Angers archivist Paul Marchegay travelled to England to document these and other French cartularies in English collections. The result of his efforts is Cartulaires Français en Angleterre (1855). This important bibliography provides full descriptions of seven French cartulary manuscripts held at the British Museum, lists by geographic location twenty-two documents pertaining to French foundations, and describes the two manuscripts held in the Phillipps collection. It both represents an important contribution to the history of Angers and reveals a fascinating story of diplomatic co-operation among the archivists of France and England.