973 Harald Bluetooth crossed the Eider river

Holy roman emperor Otto 2(955-983)
Local kings assembled in Chester to acclaim the English king, Edgar. Among these was King
Magnus (Maccus) Haraldsson who was ‘king over many islands’. He may have been a son of  Harald Sigtryggsson in Limerick and among those who were sent into exile when Limerick was conquered.  Magnus controlled the Hebrides and was a friend of the king of Dublin. The Irish refer to the kings who ruled Man and the Isles as Ri Innsi Gall.
Emperor Otto the first`s death on the 7th of May made Harald Bluetooth cross the Eider to expand the Danish border. The new holy Roman emperor Otto the second, was only 19 years old, and decided to create an army, which was ready and moved into Denmark the next year.