In the first year of his reign as king of Ireland, 916, Niall Glúndubh, as already told, restored the Assembly of Taillte. In the following year, 917, he marched against the Norsemen of Waterford. They came out to meet him. An indecisive action was fought. Then both armies fortified themselves in the field, anticipating the modern manner of warfare, and remained thus face to face for three weeks. Niall meanwhile sent to the king of Leinster requesting him to attack the Norsemen from that side. The Norsemen, however, did not wait for this attack. Keeping enough force to hold their position against Niall, they sent their main body to meet the Leinstermen, whom they completely defeated. The place of this encounter is named Cenn Fuait, and was absurdly identified by O'Donovan with Confey in Co. Kildare, apparently on the principle that there is an M in Macedon and also in Monmouth. The battle must have taken place close to Waterford Harbour on the Leinster side. Other editors of the annals content themselves with repeating O'Donovan's conjecture as authentic. After this failure, Niall withdrew, and the Norsemen held Waterford from that time until the Norman invasion. Next year 918, Niall opened war on the Norsemen of Dublin. That is just 1000 years ago. The following year, 919, he led an army against Dublin. The Norsemen met him on the north bank of the Liffey at Islandbridge. Niall was defeated and mortally wounded. This battle is sometimes called the battle of Dublin, sometimes the battle of Cell-mo-Shámhóg, from a church in the vicinity. The latter name furnished O'Donovan with the occasion for another conjectural identification, which other editors have blindly followed. He made Cell-mo-Shámhóg to be the same as Kilmashogue, six or seven miles from Dublin on the south side and among the hills. A little reflection would have assured these editors that, just as a Leinster army coming to the relief of an army near Waterford was not likely to encounter the Norse of Waterford in the north of Leinster, so also an army from northern Ireland was not likely to meet the Norsemen of Dublin in the mountains to the south of Dublin. For the full identification of the battle site, the student may refer to the name Cell Mo Shámóc in Father Hogan's Onomasticon. From Niall Glúndubh the O'Neills of Tyrone derive their surname and descent.