Ireland has been formally identified with Celts since the 16th century, though Celts influenced Irish history before then. Julius Caesar's commentaries divide Gaul (not the British Isles) "into three ethnic regions, by no means culturally or linguistically identical: Celtae, Aquitani, and Belgae" (Rankin 2), placing them on the Continent. Early Irish mythic sources, partly taking their cue from classical descriptions of the Celts as Scoti, identified themselves with Scythians, who flourished in ancient Asia Minor. However, La TFne Iron Age artwork, designating the Continental encounter of Celts, Greeks, and Etruscans and characterized by highly stylized and abstract animal and geometric design, was found in Ireland that dated from the third century BC. That suggests that Celts, migrating ubiquitously across Europe, were already in Ireland.
According to Irish legend, Scota, a pharaoh's daughter, voyaged to Ireland about 1000 BC and married the Spanish conqueror Milesius (Rankin 26). Accordingly, the Irish are "popularly known as the Milesian Race" (MacManus 1). Scotia was Ireland's name at one period (MacManus 8). Rankin argues that the Celts in Ireland may have invaded and mingled with indigenous peoples preexisting there and in their turn were mingled with by various waves of invading tribes, with the last of that lot identified as Gaels. Linguistic cognates and myth suggest that Gaels originated from Spanish Celts (14), which brings the Milesian legend full circle. According to legend, the Milesians overtook but did not exterminate Firbolg and Tuatha De Danann peoples in Ireland and were later subsumed by Gaels. The Gaelic identity dominated Ireland afterward (MacManus 1).
The Milesian legend, or anyway the legend that explained the Milesian dominance over the other two peoples of Ireland, helps explain why Celtic culture evolved as the military aristocracy that has been deduced from the archaeological and mythic record. MacMan...