referred to simply as "Osraige" in most annals for the period. Despite its fracturing, Osraige was still powerful enough to oppose and inflict defeats upon Leinster. As retribution in 1156–7, the high king Muirchertach Mac Lochlainn led a massive campaign of destruction deep into Osraige, laying waste to it from end to end, and officially subjected it to Leinster. Decline during the Norman Invasion (1165–1194) Much of the background drama and initial action of the Norman advance played out on the battlefields and highways of Osraige. The kingdoms of Osraige and Leinster had also witnessed increased mutual hostility prior to the Normans. Significantly, Diarmaid Mac Murchadha, the man who would one day become king of Leinster and invite the Normans into Ireland, was himself fostered as a youth in north Osraige, in the territory of the Ua Caellaighes of Dairmag Ua nDuach who sought to undermine their Mac Giolla Phádraig overlords. In the 1150s, high king Muirchertach Mac Lochlainn made a devastating punitive campaign on the divided Osraige, burning and pillaging the whole kingdom and subjected it to Leinster overlordship. Thus, Diarmaid Mac Murchadha came to intervene several times in the disputes of Ossorian succession. After Mac Murchadha's exile and return in 1167, tension was heightened between Osraige and Leinster by the blinding of Mac Murchadha's son and heir, Éanna mac Diarmat by the prince of greater Osraige, king Donnchad Mac Giolla Phádraig. Mac Murchadha's initial mercenary force under Robert FitzStephen landed close to the border of Osraige at Bannow, took Wexford and immediately turned west to invade Osraige, acquiring hostages as a nominal token of submission. Later still, another auxiliary force under Raymond FitzGerald (le Gros) landed just opposite Osraige's border at Waterford, and won a skirmish with its inhabitants. By 1169, Richard de Clare, 2nd Earl of Pembroke (Strongbow) had also landed with a major force outside of Waterford, married Mac Murchadha's daughter Aoife and sacked the city. Later that year, a major conflict was fought in the woods of Osraige near Freshford when Mac Murchadha and his Norman allies under Robert FitzStephen, Meiler FitzHenry, Maurice de Prendergast, Miles FitzDavid, and Hervey de Clare (Montmaurice) defeated a numerically superior force under Domnall Mac Giolla Phádraig, king of greater-Osraige, at the pass of Achadh Úr following a feigned retreat in a three-day battle. Shortly thereafter, de Prendergast and his contingent of Flemish soldiers defected from Mac Murchada's camp and