also several other bases in western Ireland. Given its strategic location at the mouth of the Shannon estuary, it controlled all maritime traffic up the Shannon to Limerick. The Annals of Inishfallen record that during the 970s, Norse kings of Limerick were resident at Inis Cathaigh. Ivar of Limerick, the last Norse king of the city, along with two of his sons, was slain on Inis Cathaigh by Brian Boru in 977. Later ecclesiastical history After the Synod of Ráth Breasail in 1111 a canonical diocese of Inis Cathaig (the spelling then current) was established. This was absorbed by the Diocese of Killaloe in 1189, but was restored by Pope Innocent VI and continued as a separate see under Bishop Thomas (1358–68). In 1378 its possessions were divided, and the island remained a portion of the Diocese of Killaloe, being later merged into the parish of Kilrush. However, there is mention of an Englishman, John Grene, as Bishop of Inis Cathaig in 1467. Inis Cathaigh is now listed among the titular sees of the Catholic Church. Titular bishops of Inis Cathaigh: Thomas Jerome Welsh (1970–1974) William Anthony Hughes (1974–1979) John Edward Heaps (1981–2004) Frank Joseph Caggiano (2006–2013) Artillery battery Scattery artillery battery, located on the south of Inis Cathaigh, was built during the Napoleonic Wars and is preserved quite well. The Shannon Estuary was one of three invasion places the French had considered along the west of Ireland. As such, places along the estuary were considered for establishing a defence. Inis Cathaigh is one of six batteries in the estuary. It was chosen on the proposal of defected French general Charles-François du Périer Dumouriez. The battery forms a semi-circular D shape with a dry moat. The battery main armament consisted of six 24-pounder long guns arranged along the length of the curved D. These were mounted on traversing mounts in purpose built gun emplacements. Each gun could traverse 90 degrees on its mount, giving the battery a total engagement angle of over 200 degrees. These could fire out over the estuary and coordinated crossfire was possible with its southern shore sister battery on Carrig Island. The block house barracks had two 5½ inch howitzer gun emplacements on the roof for close quarters defence of its vulnerable rear, but these could be deployed to any incident due to their 360 degree mounting platforms. The choice of 5½ inch made interoperability of