I like the story of the Milesian invasion, where they defeated Mac Cuill, Mac Cecht, and Mac Greine, the three last kings of the Tuatha De Danaan. As I understand it they split Ireland between two of the sons of Mil, Erimon and Eber Finn. Then at one point the two sons fought each other, and Eber Finn was killed, leaving one ruler. After this point, what happens to the last son, Erimon? Who eventually takes over Ireland after his reign?