885 – Murder of Godfrid, Duke of Frisia
Godfrid was a Dane who joined Rorik of Dorestad on his adventures in Frisia. After Rorik dies, Gudred is appointed Duke of Frisian in 882 by Charles the Fat. At one point, he tries to outsmart Charles the Fat who has him murdered instead.
Read more on Gjallar (also available in English).
1040 – Coronation of Harthacnut III, son of Cnut the Great, as King of England.
After the death of Cnut the Great, his sons challenged each other for succession. Harald Harefoot came out victorious and Harthacnut remained king of Denmark. When Harald died without an heir, Harthcnut returned to England to claim the throne.
Read this fine article on The History Jar.