Facts and Events
Sitric commanded Viking forces in the Battle of Confey and other battles, the Annals of Ulster records the arrival of two viking fleets in Ireland in 917, one led by Ragnall ua Ímair and the other by Sitric, both of the House of Ivar. They were victorius at the Battle of Kylmehauog (near Islandbridge in County Dublin) on 14 September 919 fought with Niall Glúndub, the King of Ailech, this was possibly the most devastating defeat ever inflicted on the Irish by the Norse, and according to the annals Sitric then "entered Áth Cliath", i.e. Dublin, which presumably means that he took possession of it. Ragnall, after occupying Waterford, went on to Scotland, then conquered York and became king there. Sitric fought several battles with Niall Glundub. Sitric's possession of Dublin seemed secure, Sitric however left Dublin in 921, the pious annalist claims he left "through the power of God".
After leaving Dublin Sihtric replaced Ragnall ua Ímair on throne of York in 921. Sitric attacked Mercia from the Mersey which formed part of the border between Mercia and the Viking Kingdom of York. In 926 he married King Æthelstan's sister, possibly Edith of Polesworth, in a political move designed by Athelstan to build up his influence in the north of England. Sitric died suddenly only a year later in 927 and Athelstan assumed his throne.
Sitric's son, Amlaíb Cuarán later succeeded him both as king of Dublin and of York and married Gormflaith ingen Murchada. His son Gofraid mac Sitriuc ruled Dublin. A third son Harald ruled Limerick and died in 940.