deep access into Osraige's interior. Vikings came into conflict with the Irish on the River Suir as early as 812 and a large fleet sailed up the Barrow and Nore rivers, inflicting a devastating rout on the Osraige in 825. A Norse longphort was planted by Rodolf son of Harald Klak at Dunrally between 850–62 on the border with the neighbouring kingdom of Laois. Other longphort settlements emerged at Woodstown (c.830–860) and Waterford in 914. Consequently, Osraige endured much tumult and warfare but subsequently emerged politically dominant, becoming a major force in southern Ireland and even the one of the most militarily active kingdoms on the island by the middle of the ninth century. Originally granted semi-independent status within the province of Munster, the war-like and victorious rule of king Cerball mac Dúnlainge birthed a dramatic rise in Osraige's power and prestige, despite a heavy influx of Viking marauders to Ireland's shores. Under the long reign of Cerball mac Dúnlainge between 843/4 to 888, Osraige was transformed from a relatively unimportant kingdom into one of Ireland's most powerful overlordships, which surpassed that of both Munster and Leinster and even threatened Uí Néill hegemony over southern Ireland. There is circumstantial evidence which indicates that early in his reign, Cerball may have even sent emissaries to establish international diplomacy with the Carolingian Empire's western-third under Charles the Bald who was also dealing with Viking threats. He established dual marriage alliances with the High King Máel Sechnaill mac Máele Ruanaid and successfully forced Máel Gualae, king of Munster to recognize Osraige's formal independence from Munster in 859. The later Icelandic Landnámabók uniquely names Cerball as king of Dublin and the Orkney islands during his reign, yet scholars regard this as an interpolation borrowed from the influential narrative found in the Fragmentary Annals of Ireland, likely composed by Cerball's eleventh century descendant Donnchad mac Gilla Pátraic. Cerball's descendant king Gilla Pátraic mac Donnchada (r. 976–996) proved an able ruler, and by the late 10th century the hereditary ruling descendants of Osraige had adopted the surname Mac Giolla Phádraig as their patronymic. By the late tenth century, Osraige was brought into conflict with the ambitious Dalcassian king Brian Boruma, who gained supremacy over all Ireland before being killed in the Battle of Clontarf in 1014, in which the Ossorians did not partake. The Cogad Gáedel re Gallaib relates a story that victorious but wounded Dalcassian