Tara was first the capital of the Firbolg, the mythical People of the Bag who settled in Ireland after fleeing from Greece, where they were enslaved and forced to carry earth in bags.

The Firbolg made ships out of the bags and sailed to Spain, then to Ireland, which they ruled until the coming of the Tuatha de Danaan (Gaelic for People of the Goddess Danu). Later, Tara was the capital of the Milesians, also known as the Gaels, who are rumoured to have arrived in Ireland 1500 years before Christ was born.