Breogán is a character in the Lebor Gabála Érenn, a medieval Christian history of Ireland and the Irish. He is supposedly the son of Brath, and is described as an ancestor of the Gaels. The Lebor Gabála purports to be an account of how the Gaels descend from Adam through the sons of Noah and how they came to Ireland.
It tells us that they spent 440 years wandering the Earth and underwent a series of trials and tribulations, which is based on the tale of the Israelites in the Old Testament. Eventually, they sail to Iberia and conquer it. There, one of their leaders, Breogán, founds a city called Brigantia and builds a great tower.
Wikipedia https://en.wikipedia.org/wiki/Breogán
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