The Iron Age in Ireland is traditionally associated with people known as the Celts. The Celts were commonly thought to have colonised Ireland in a series of invasions. The first Celtic-speaking tribes are believed to have arrived on the island about 600 BC in what is referred to as the Hallstatt era.
Other colonists followed them, the main thrust arriving in the later La Tene era some time between the third and first centuries BC. They came from neighbouring Britain, Gaul and Iberia: tribes from two main stems of the Continental Celts—the Belgae originating in northern Gaul and the Gael from southern Gaul and the northern seaboard of the Iberian Peninsula.