[2][3] According to an ancient tradition recorded in Lebor Gabála Érenn, three rivers "burst forth" during the reign of Fíachu Labrainne as High King of Ireland.

The Metrical Dindshenchas records Inber Cíchmaine, cid cress, gáet co líth-baile láech-bress Maine ergna, úais ella, mac Medba ocus Ailella.

("At Inber Cichmaine, though it be narrow, was slain (a mighty onslaught) far-famed Maine, son of Medb and Ailell, exulting in fury of warlike combats.

")[4][5] A possible etymology is from Old Irish mang, referring to a fawn or young deer.

In Castlemaine it passes under the N70, flows past the Ardcanaght Stones and enters the harbour.