The last strong Ui Dunlainge king of the Laigin in the period before the Battle of Clontarf, Cerball mac Muireccain belonged to the lineage of Ui Faelain. His father Muireccan, styled rex Naiss & Airthir Liphi (king of Naas and the eastern Liffey-Plain), was slain by the Vikings in 863. Of his brothers, Domnall, his predecessor-but-one in the kingship, was killed by his own retainers in 884, while Maelmorda, who fell fighting the Vikings at Cenn Fuait (perhaps Confey, Co. Kildare) in 917, was ancestor of most of the later Ui Faelain rulers.
It seems that, especially in the earlier years of his reign, Cerball struggled to enforce his authority against counter-claims by rival Ui Dunlainge lineages— including Ui Muiredaig and Ui Dunchada. The acknowledgement as tanaiste of Bran (d. 894), son of his immediate predecessor Muiredach of Ui Dunchada, perhaps represented a concession to that lineage. Aside from intradynastic challenges, Cerball faced a protracted conflict with the neighboring kingdom of Osraige, ruled by the sons of Cerball mac Dungaile. A poem in the Book of Leinster, "The Quarrel about the Loaf," which tells of contention between an old woman of Leinster and a Munster soldier over billeting rights, is a metaphoric account of a border dispute concerning Mag Dala, a plain in south County Laois. The poem preserves a catalogue of Cerball’s subkings, and it is probably significant that all but one are from north Leinster dynasties. Ui Dunlainge was apparently under considerable strain by the late 890s; a garbled entry in AFM, as viewed by Byrne, records the celebration by Diarmait son of Cerball mac Dungaile of the Oenach Carmain, in effect a claim on the overkingship of Laigin. Confronted by such pressures, Cerball mac Muireccain sought alliance with Clann Cholmain, a powerful lineage of the Southern Ui Neill. He married Gormlaith daughter of Flann Sinna, king of Tara, but it is not stated that she was the mother of his son Cellach (sl. 924). His wife, according to a poem in the Book of Leinster, arranged the murder of Cellach Carmain and his wife Aillenn—dynastic rivals who perhaps belonged to Ui Muiredaig.
Clearly, Cerball did benefit from his alliance with the Ui Neill over king. In 902, with forces from the midland kingdom of Brega, he attacked Dublin and expelled its Hiberno-Scandinavian rulers. For a time, at least, one major threat to Ui Dunlainge had been removed. Four years later, he joined his father-in-law, Flann Sinna, in a preemptive strike against Osraige and Munster. They pillaged their way from Gabran (Gowran, Co. Kilkenny) across to Limerick. When the Munstermen retaliated in 908, Cerball supported Flann in blocking an invasion force at Belach Mugna (Ballaghmoon, Co. Kildare); the fatalities included Cormac mac Cuilennain, king of Cashel, and Cellach son of Cerball mac Dungaile, king of Osraige.
The accounts of Cerball’s death are difficult to reconcile. Whether or not he sustained wounds at Belach Mugna, as claimed by a text in the Book of Leinster (which also alleges that he mistreated his wife, Gormlaith), he died the following year. A colorful story in the so-called Fragmentary Annals tells of a horse-riding accident at Kildare, whereby he fell backward onto his own spear, which was held by a servant. The Book of Leinster kinglist echoes the line concerning a fall onto a spear—perhaps a metaphor for assassination— however, the invariably staid AU merely records in somber tone that he "died of a sickness." There is a strong tradition that he was buried at Cell Corbbain, probably located in the vicinity of Naas, County Kildare, where he is said to have maintained his court.
Certainly Cerball made a marked impression on the historical consciousness of Leinster. He is the subject of several praise-poems ascribed to Dallan mac More, reputedly his court poet, and of elegies attributed to Dallan and to Gormlaith. One poem, the "Song of Cerball’s Sword," credits him with a strike against the Ui Neill royal site of Knowth, which appears fanciful in the light of the surviving record. It is doubtful whether, earlier in his reign, he would have had the resources to invade the Ui Neill realms or, in the later years reason to do so, given his alliances with the kings of Tara and Brega. However, his achievement in bringing relative stability to Ui Dunlainge, in stalling Osraige expansion, and in removing—albeit temporarily—the threat from Scandinavian Dublin was presumably noted. Even AU styles him rex optimus Laginentsium— a most excellent king of Leinster.
