902 - Vikings driven out of Dublin

Ireland
Irish kings Cerball mac Muirecáin King of Leinster and Máel Findia mac Flannacáin King of Brega attacked the vikings in the longphort Ath Cliath (Dublin) from the north and the south, and they drove the vikings out of the area.
Wales
Ingimundr and the defeated Dublin Vikings sailed across the sea to Wales. They were opposed by Welsh forces under the command of either Hywel ap Cadell ap Rhodri Mawr or his brother Clydog, driving the Norsemen into the vicinty of Chester.
England

On December 13 the Anglo-Saxon army in Kent fought the Vikings of East Anglia at the Battle of the Holme. Æthelwold ætheling was killed during the battle and the rebellion against Edward the elder stopped.  Kentish ealdorman Sigewulf, and his kinsman Sigehelm, and almost all the Kentish slain.  For King Edward, however, the pretender, was dead and it would be Edward who in the subsequent decades conquered all of Viking-held England south of the Humber.