Snámh Dá Éan is the name of a ford on the River Shannon. Nár was married to the warrior woman Estiu. Her lover was the fairy Buide. He and his foster-brother would change into birds and sing Nár to sleep so the lovers could tryst. Nár found out and killed the birds and then both he and Estiu died from grief.
The Metrical Dindshenchas poem/story 127
I will tell you truthfully the names of the birds from whom Snam Da En is called: a tale of wrongs that confronts this concourse, the origin of the ever-glorious Crossing. Nár son of Fiacc son of curled Conall, whose words were not the words of ignorance, had to wife the lovely woman Estiu, the woman-warrior ever-white. Buide son of Derg, by full right, from the hilly ground of Dubthir, was famous Estiu's lover—Buide son of Derg, bold of hue. Buide son of Derg, ready in hospitality, and Luan his foster-brother visited bright Estiu in the shape of two birds, a lovely sight. Then they chanted to the host a song, shrill, wistful, unceasing, till all the host fell asleep at the song of the fairy-folk. While all thus slept a long sleep, they came in their proper shape, and Buide (small wonder) shared Estiu's bed. Then Nár inquires of them from his druid (earnest was their converse), from what part come the birds to beautiful stately Estiu. Then said the druid: ‘We shall not hide it from thee, O King! the birds that come hither are Buide and Luan—no sluggard is he.’ Then the birds come, as they were wont, upon the ford: in an evil hour they came to the tryst, and Estiu came to meet them. Conall Cernach's son's son came on them from behind, heavy was the harm! and hurled his spear—strong was his cast—and slew them at one shot. A little life remained in Luan, so that he reached the cool ford, and above by the ford died Luan son of Lugair son of Lugaid. Estiu went along the riverside, and no short race she ran: from her is named the plain where she died in Mag Esten. Nár went to Moin Tire Nair, after their tryst failed, and died of sorrow for his wife—Nár son of Fiac, one that never fled. Hence comes the name Ath Luain, and Snam Da En therewith, and Moin Tire Nair—glorious the meeting!—and Mag Esten, by Shannon with its crossings.
Brian Boru, last great High King of Ireland, died 1002yrs ago today at the Battle of Clontarf. He shattered a combined host of Vikings and Leinstermen, but died, along with his heir, Murcadh. Robert E. Howard chronicled the last day of King Brian (whom he greatly admired) in The Grey God Passes.