troops were challenged to battle by the Ossorians as they were returning home through Osraige after the battle of Clontarf, but some authors doubt the validity of this story, as the source is widely considered later Dalcassian propaganda. Osraige during the First Irish Revival (c. 1015 – 1165) During the period after the decline of Viking threats, many of Ireland's smaller kingdoms became dominated by larger ones, in a natural yet bloody evolution towards centralized monarchy. Various families contended for the high-kingship. Allegiance with Osraige could make or break a king's bid for the high-kingship, although the kings of Osraige never attempted the position themselves. King Donnchadh mac Gilla Pátraic, arguably Osraige's most powerful ruler who brought the kingdom to the zenith of its power, plundered Dublin, Meath and successfully conquered neighbouring Leinster in 1033, held the Óenach Carmán and ruled both kingdoms until his death in 1039. In 1085 and 1114, the city of Kilkenny was burned. Additionally, major changes to the structure and practices of the Irish Church brought it away from its historic orthodox practices and more in line with the massive Gregorian Reform movement which was already taking place on the continent. Significantly, the Synod of Rath Breasail was part of this movement, likely held in the northernmost territory of Osraige in 1111. By the early-12th century, fighting had erupted within the dynasty and split the kingdom into three territories. In 1103, Gilla Pátraic Ruadh, king of Osraige and many of the Ossorian royal family were killed on campaign in the north of Ireland. Two new claimants to the throne then emerged, both scions of the Mac Giolla Phádraig clan. Domnall Ruadh Mac Gilla Pátraic was the king of greater Osraige, often called Tuaisceart Osraige ("North Osraige") or Leath Osraige ("Half-Osraige"); and Cearbhall mac Domnall mac Gilla Pátraic in Desceart Osraige ("South Osraige"), a smaller portion of the southernmost part of Osraige bordering Waterford. Additionally, the Ua Caellaighe clan of Mag Lacha and Ua Foircheallain in the extreme north Osraige declared their independence from Mac Giolla Phádraig rule under Fionn Ua Caellaighe. Thus the north and south fringes of the kingdom broke apart from the centre, each with subsequent competing dynasts until the arrival of the Normans. While the north and south extremities of the kingdom were broken away, the majority of central Osraige around the fertile Nore valley maintained greater stability and is most often