Cerball mac Dúnlainge (died 888), King of Osraige aligned himself with the Danes versus the Norse to become the most powerful ruler in southern Ireland during this period.
[7] In 856 a Norse force slew Gormán son of Lonán, heir designate of Cashel, at Loch Cenn.
[8] In 857 Cerball and his Danish allies, Amlaíb Conung and Ímar, won a victory over the Norse and Gall Gaeill under Kettil "The Fair" in the Munster territory of Arad Tíre in northern Tipperary.
[9] In 858 Máel Sechnaill led a large muster of the men of Ireland into Munster to exact hostages.
[10] The next year however in 859 Cerball again defied Máel Sechnaill and with his Danish allies led an expedition into Mide.