Seventh archbishop of Bremen-Hamburg; b. c. 900; d. Bremen, Germany, April 28 or 29, 988 (commemorated, April 28). A Saxon and canon of Hildesheim, Adaldag was the chancellor of Emperor otto i when he succeeded unni as archbishop of the great northern See of Bremen-Hamburg in 937. Adaldag remained one of Otto's principal advisers, and when Otto deposed and abducted Pope benedict v (964), it was Adaldag who served as the pope's custodian. As archbishop, Adaldag proved energetic and effective and carried on extensive missionary activities. Under him the Danish suffragan Sees of Schleswig, Ribe, Aarhus, and Odense were founded. The Diocese of Oldenburg in Holstein was set up as a base for a reinvigorated mission to the Wends. He successfully warded off the claim of the archbishop of Cologne to metropolitan jurisdiction over Bremen.
Bibliography: adam of bremen, History of the Archbishops of Hamburg-Bremen, tr. f. j. tschan (New York 1959). o. h. may, Regesten der Erzbishöfe von Bremen, v.1 (Hanover 1928). g. dehio, Geschichte des Erzbistums Hamburg-Bremen (Berlin 1877). g. glaeske, Die Erzbischöfe von Hamburg-Bremen als Reichsfürsten (937–1258) (Hildesheim 1962).
[j. f. fahey]