CERBALL MAC DUNLAINGE (d. 888) (Medieval Ireland)

During the reign of Cerball mac Dunlainge (842-88) the Osraige rose from relative obscurity to become a major player in Irish politics. The most lavish account of his deeds survives in an eleventh-century saga embedded in The Fragmentary Annals of Ireland. This saga appears to have been written under the sponsorship of Cerball’s great-great grandson Donnchad mac Gilla-Patraic, who ruled Osraige (1003-1039) and Leinster (1033-1039). The exaggerations and anachronisms found in the saga urge a degree of caution in its use as a historical source. Cerball is also mentioned in the Icelandic Landnamabok and later sagas. These demonstrate that a number of prominent Icelandic families claimed descent from Cerball as a figure of legend.

Cerball’s kingdom, Osraige, was strategically placed between the heartlands of Munster and Leinster. At the beginning of Cerball’s reign, Osraige owed allegiance to overkings of Munster. However, in the 850s and 860s the fortunes of Munster declined, a factor that can be seen to aid Cerball’s advancement.

Nevertheless, Cerball also faced dangers from Viking incursions. He is most renowned for his victories over Vikings that are elaborated in The Fragmentary Annals of Ireland. Cerball’s first battle against Vikings is reported in 846. He also allied with some Viking groups when it suited his policies. In the late 850s he joined forces with Ivarr, a king of the "Dark foreigners." In 859, they raided Southern Uf Neill, thus challenging the power of the Uf Neill overking Mael-Sechnaill mac Maele-Ruanaid. In consequence of this attack, a royal meeting was arranged at Rathugh (Co. Westmeath) in 859. Osraige was formally ceded from Munster control and placed under the authority of Mael-Sechnaill. The event caused Cerball to reject his alliance with Ivarr. Further hostilities against Vikings are recorded for the remainder of Cerball’s reign, although a temporary alliance with one viking group is recorded in 864.


Cerball was able to deal effectively with the threats posed by other Irish kings. Cerball enjoyed good relations with the Lofgis of Leinster (his sister Lann was initially married to the king of this population group). Nevertheless, Cerball engaged in hostilities against other kings in the province on at least three occasions. The marriages of Cerball’s daughters to kings of Uf Cheinnselaig and Uf Drona in Leinster may indicate attempts to reduce border warfare.

Cerball’s relations with Munster fluctuated. In 864, he attacked the heartlands of the province. He later allied with Dunchad mac Duibdabairenn, who became overking of Munster in 872. They plundered Connacht together in 871 and 873. His alliance with Dunchad later collapsed, and Cerball campaigned in Munster in 878.

Cerball’s relations with the powerful Uf Neill rulers seem to have been flexible and pragmatic. From 859, Cerball supported Mael-Sechnaill against his rival Aed, overking of Northern Uf Neill. Nevertheless, Cerball quickly joined sides with Aed following Mael-Sechnaill’s death. Cerball’s sister Lann assisted in securing these important alliances by marrying both kings in succession.

Cerball ruled for a total of forty-six years. His longevity, success, and the dramatic potential of events in his career encouraged the later development of legends about him.

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