 She was slain by Regan after whom Tomregan is supposedly named.In ancient times the area that became to be known as Bréifne was said to be occupied by the Erdini, called in Irish 'Ernaigh', who possessed the entire country bordering Lough Erne.At the time of the Christianization of Ireland (c. 5th–6th century) groups believed to be in or near Breifne included the Glasraighe, Masraige, Dartraige, Armhaighe, Gallraighe, the Fir Manach, and the Gailenga.