 Tomrair (Þórir), the heir-designate of the King of Laithlind, was slain in a battle with Ólchobar mac Cináeda the King of Munster and Lorcán mac Cellaig the King of Leinster at Sciath Nechtain (near Castledermot in County Kildare).In the same year Tigernach mac Fócartai King of Loch Gabhair (Lagore, the royal seat of South Brega) inflicted a significant defeat on the Norsemen in an oakwood at Dísert Do-Chonna.These defeats culminated in an attack on Dublin itself in 849.