This paper provides an edition, translation and discussion of four letters written by Flemish abbots to the archbishops of Canterbury between the years 980 and 991 and preserved in two manuscripts drawn on the archiepiscopal archives in the early eleventh century (London, British Library, Cotton Tiberius A. xv and Cotton Vespasian A. xiv). The letters document the increasing importance of cross-Channel relations in the late tenth century and provide context for a number of hitherto unexplained indications of cultural, religious and financial exchanges between the county of Flanders and England.