Viking Age by a Viking leader called Bagsecg and his five earls. Aided by the Great Heathen Army (which had already overrun much of England from its base in Jorvik), Bagsecg's forces, and Halfdan's forces (through an alliance), the combined Viking forces raided much of England until 871, when they planned an invasion of Wessex. On 8 January 871, Bagsecg was killed at the Battle of Ashdown along with his earls. As a result, many of the Vikings returned to northern England, where Jorvic had become the centre of the Viking kingdom, but Alfred of Wessex managed to keep them out of
Ailill mac Dúnlainge (died 871) his camp was attacked by the Laigin who were at first successful, but in a counter-attack they were put to flight. Ailill's name is not connected with these events which state that Muiredach mac Brain was the King of Leinster who fought the forces of Cerball. The "Fragmentary Annals" give a lengthy account of this event and state that Cerball met up with the high king's forces at Belach Gabrán (the pass of Gowran in east-central Osraighe) but both forces then retired and the hostages of the Laigin were not taken. In 871 Ailill was killed by the Vikings of