to counter the Norman invasion of Ireland. Ua Conchobair was comfortable at Cnuch having overcome his Danish vassals in the Kingdom of Dublin some years previously. The siege exerted pressure on the forces of the Cambro-Norman leader, Strongbow, who asked the Archbishop of Dublin, Lawrence O'Toole to negotiate with the High King at Cnucha. Strongbow's offer to recognise Ua Concubhair as High King was rejected. He was commanded to depart from Ireland immediately. Strongbow was furious but Maurice de Prendergast, who had accompanied Archbishop O'Toole, had observed that the Irish troops were largely inactive and unready for battle. His report to Strongbow spurred him to lead a successful attack against the High King's armies. Ua Concubhair fell back from Cnucha and the other Irish Chiefs returned to their territories. The battle was lost and the Norman conquest of Ireland was successful. Following the siege, the Normans realised the strategic importance of the location which looked over the city of Dublin. Consequently in 1177, a feudal barony of Castleknock was created out of the Lordship of Meath by Hugh de Lacy, Lord of Meath who granted it to Hugh Tyrrel. It was held for three and a half knight's fees, owed to the superior Lord of Fingal. The title and lands of Castleknock were held by the Tyrell family until 1370 when Hugh Tyrell and his wife died of the Plague. It passed by inheritance to the Burnell family. The first Baron, Hugh Tyrrel, gave lands in the barony at Kilmainham to the Knights of St. John whose legacy continues in the area today in the form of St. John Ambulance. Later, civil parishes, based on the boundaries of the ecclesiastical parishes of the Established church were used to sub-divide the barony. In 1185, the second baron, Richard de Tyrell, gave a grant of land to the Benedictine Monks of the Abbey of Little Malvern, Worcestershire, to endow a religious house at Castleknock in honour of Saint Brigid. Later they built a chapel, the White Chapel at Coolmine, which served the parish of Clonsilla. In 1219 the great tithes of the parish were appropriated by Archbishop Henry de Londres to the Priory of Malvern on condition that they should add five monks to their number. In 1225 the monks granted half of the tithes of the manor of Castleknock to the use of St Patrick’s Cathedral, renouncing to the Archbishop all