Mongfind (Modern Irish: Mongfhionn, literally "fair/white hair") is a figure from Irish legend. She is said to have been the wife, of apparent Munster origins, of the legendary High King Eochaid Mugmedón and mother of his eldest three sons, Brión, Ailill and Fiachrae, ancestors of the historical Connachta. She was Eochaid's first wife; his second wife, Cairenn, gave birth to Niall of the Nine Hostages. Several tales depict Mongfind as an adversary of Niall. Mongfind is also said to have been the sister of Crimthann mac Fidaig, King of Munster and the next High King of Ireland, whom she is said to have killed with poison in a bid to make her son king.[1][2] She drank the poisoned drink to convince Crimthann, and died soon after at Samhain.[2][3]
According to Cormac's Glossary,[4] she was a goddess the pagan Irish worshipped on Samhain. This was also called the Féile Moingfhinne i.e. "Festival of Mongfind".[2][3] Later legend, as documented in Patrick Weston Joyce's Social History of Ancient Ireland, makes her a banshee. A prominent hill called Cnoc Samhna ("Hill of Samhain")[5] or Ard na Ríoghraidhe ("Height of the Kingfolk") in County Limerick is associated with a tale linked to Mongfind. "Anocht Oíche Shamhna Moingfhinne banda" is children's rhyme from County Waterford which translates as "Tonight is the eve of Samhain of Mongfhionn the goddess".[citation needed]
Variant spellings of her name include Mongfhind, Mongfinn, Mongfhinn and Mongfionn.
Mongfind and her brother, children of Fidach and grandchildren of Dáire Cerbba in most sources, are sometimes said to belong to an early or peripheral branch of the Eóganachta. However, this is unlikely, as the evidence suggests that, if historical, they belong to a distinct people associated with other kingdoms, possibly the Dáirine, who may be referred to as their people in an obscure poem in Old Irish by Flann mac Lonáin (d. 896).[6] In the Banshenchas she is called "Mongfind of the Érnai" (Érainn), and given a later son Sidach following the Connachta.[7] Dáire Cerbba is stated in Rawlinson B 502 to have been born in Mag Breg (Brega), Mide,[8] much of which probably remained Érainn territory at the time of his supposed floruit. It is difficult to distinguish the Dáirine from the Érainn in the surviving corpus.