Ireland in the period was a patchwork of petty statelets, fused together and driven apart by tribal loyalties, often given to a state of war. Other realms from across the water in
Great Britain and in particular
Scotland frequently became involved in the affairs of Ireland, notably the Scottish branch of
Dál Riata, which had originally been from north of
Lough Neagh but expanded across to Scotland. Indeed, the tribal loyalties often spilled across the
Irish Sea, where the same clans could be found on either side, especially in Scotland. Rivalries and alliances between the petty kingdoms changed frequently. For example, Dál Riata, which fought with Congal in this battle, had seen
one of their kings killed by his brother at the
Battle of Fid Eoin (either 629 or 630). Congal himself had first established his power base in Dál Riata, where he became King, before being recognised as
King of Ulaid in 627. His ambitions soon came into conflict with Domnall II, who became High King of Ireland in 628. Ironically, Domnall II only rose to such a position because Congal had defeated and killed the previous High King,
Suibne Menn, (who was Domnall's distant cousin in the
Uí Néill dynasty) in a previous battle. Domnall at first launched a raid into
Leinster in 628 to secure his authority as High King. Some primary sources state that Congal had initially become the
Ard Rí following his defeat of Suibne Menn. It may be therefore that Domnall seized the position indirectly from his Ultonian rival. Regardless, the two had become enemies. Domnall pressed this rivalry very quickly, and in 629 the two kings engaged each other at the Battle of Dún Ceithirn in what is now
County Londonderry. On this occasion Congal was defeated and fled to Scotland to seek support, and Domnall was left unchallenged as the High King. Throughout the 630s, Domnall continued to wage war on his rivals in the Uí Néill clan. In 637, however, Congal once again rose to challenge the Ard Rí, and enlisted the help of the Dál Riata to do so. Congal returned from Scotland, gathered his native Irish armies which were supported by a more diverse Dál Riata army consisting of many British soldiers, particularly Scots. ==Location==