Fir Ol nEchmacht was the name of a group or race of people living in pre-historic Ireland. The name may be translated as "men (Irish, Old (to 900);: Fir) of the race/people (Irish, Old (to 900);: Ol, possibly Irish, Old (to 900);: Dal?) of Irish, Old (to 900);: Echmacht" (Irish, Old (to 900);: Echmacht being the given name of the people, perhaps from ech, "horse," and macht, "death/wonderful/across the sea").[1] Some scholars believe they are connected to, or the same as, the Nagnatae tribe, mentioned in Ptolemy's 2nd century AD work Geography.[2]
Virtually all of Ireland west of the Shannon was once named after them and was called Cóiced Ol nEchmacht until the early historic era (5th-7th centuries).
It was only with the rise of the Connachta dynasty that the term Fir Ol nEchmacht was dropped and the province was renamed Connacht.