Osraige in the Viking Age (795–1014) Osraige

the south-east of ireland c. 900. dotted line denotes osraige s borders.

because osraige bound major rivers, period witnessed establishment of several significant viking bases on , around kingdom s borders in ninth , tenth centuries; nore, barrow , suir watershed systems providing deep access osraige s interior. vikings came conflict irish on river suir 812 , large fleet sailed barrow , nore rivers, inflicting devastating rout on osraige in 825. norse longphort planted rodolf son of harald klak @ dunrally between 850–62 on border neighboring kingdom of laois. other longphort settlements emerged @ woodstown (c.830–860) , waterford in 914. consequently, osraige endured tumult , warfare subsequently emerged politically dominant, becoming major force in southern ireland , 1 of militarily active kingdoms on island middle of ninth century. granted semi-independent status within province of munster, war-like , victorious rule of king cerball mac dúnlainge birthed dramatic rise in osraige s power , prestige, despite heavy influx of viking marauders ireland s shores.

under long reign of cerball mac dúnlainge between 843/4 888, osraige transformed relatively unimportant kingdom 1 of ireland s powerful overlordships, surpassed of both munster , leinster , threatened uí néill hegemony on southern ireland. there circumstantial evidence indicates in reign, cerball may have sent emissaries establish international diplomacy carolingian empire s western-third under charles bald dealing viking threats. established dual marriage alliances high king máel sechnaill mac máele ruanaid , forced máel gualae, king of munster recognize osraige s formal independence munster in 859. later icelandic landnámabók uniquely names cerball king of dublin , orkney islands during reign, yet scholars regard interpolation borrowed influential narrative found in fragmentary annals of ireland, composed cerball s eleventh century descendant donnchad mac gilla pátraic.

cerball s descendant king gilla pátraic mac donnchada (r. 976–996) proved able ruler, , late 10th century hereditary ruling descendants of osraige had adopted surname mac giolla phádraig patronymic. late tenth century, osraige brought conflict ambitious dalcassian king brian boruma, gained supremacy on ireland before being killed in battle of clontarf in 1014, in ossorians did not partake. cogad gáedel re gallaib relates story victorious wounded dalcassian troops challenged battle ossorians returning home through osraige after battle of clontarf, authors doubt validity of story, source considered later dalcassian propaganda.