ÃÂed Rúad, son of Badarn, DÃÂthorba, son of Deman, and Cimbáeth, son of Fintan, three grandsons of Airgetmar, were, according to medieval Irish legend and historical tradition, High Kings of Ireland who ruled in rotation, seven years at a time. They each ruled for three seven-year stints. ÃÂed died at the end of his third stint, by drowning in a waterfall which was named Eas Ruaid, "the red's waterfall" (Assaroe Falls, Ballyshannon, County Donegal), after him; previously the waterfall had been called Ess Duinn, the "Rapid of Donn", and his death is described as a miracle of sea and mighty wind. DÃÂthorba and Cimbáeth then took their turn, after which ÃÂed's daughter, Macha Mong Ruad, demanded to rule in her father's place. DÃÂthorba and Cimbáeth refused, and battle ensued. DÃÂthorba was killed. Macha forced DÃÂthorba's sons to build her a palace at Emain Macha. She married Cimbáeth and the pair ruled for a further seven years, at the end of which Cimbáeth died of plague, and Macha became the only queen in the List of High Kings of Ireland.
The sources differ as to how the rotation worked. The reigns of Aéd and DÃÂthorba are missing in the Lebor Gabála ÃÂrenn â after the previous High King, Lugaid Laigdech, is killed by ÃÂed, a dinsenchas story about the founding of Emain Macha is interpolated, followed by the reign of Cimbáeth, who is said to have succeeded DÃÂthorba and ruled for twenty-eight years. The dinsenchas story tells how each of the three cousins ruled for seven years in turn, and each ruled three seven-year stints; the Annals of the Four Masters agrees, but Geoffrey Keating gives them each a single reign of twenty-one years each, except for Cimbáeth, who rules for twenty. The Lebor Gabála synchronises Cimbáeth's reign to that of Alexander the Great (336âÂÂ323 BC). The chronology of Keating's Foras Feasa ar ÃÂirinn dates their combined reigns to 530âÂÂ469 BC, the Annals of the Four Masters to 731âÂÂ661 BC.