of Leinster. Yet, T. F. O'Rahilly considered Loegaire Bern Buadach, the mythical ancestor Dál Birn, was the 'same personage as the Loegaire Buadach of the Ulidian tradition' and, therefore, were not Laigin. Déisi, Corcu Loígde usurpation and Christianization (c.450–625) Several sources indicate that towards the end of the fifth century the Osraige ceded a swath of southern territory to the displaced and incoming Déisi sometime before 489. The traditional accounts states that the landless, wandering Déisi tribe were seeking a home in Munster, through the marriage of their princess Ethne the Dread to Óengus mac Nad Froích, king of Munster. As part of her dowry, Ethne asked for the Osraige to be cleared off their land but were repulsed several times by the Osraige in open battle before finally overcoming them through magic, trickery and guile. The account mentions that at this defeat, the Ossorians fled like wild deer ("ossa" in Irish), a pun on their tribal name. It appears that soon thereafter following this defeat, the hereditary Dál Birn kings were displaced for a period by the Corcu Loígde of south Munster. The Dál Birn remained in control of their northern territory while Corcu Loígde kings ruled the greater portion of southern Osraige around the fertile Nore valley until the latter part of the sixth century and the rise of Eóganachta dominating Munster. The new political configuration, probably the result of an Uí Néill-Eóganachta alliance against the Corcu Loígde, caused a reduction in Osraige's relative status. In 582, Fergus Scandal mac Crimthainn, the king of Munster, was slain by Leinstermen and Osraige was therefore ceded from Leinster as blood-fine payment and attached the kingdom to the province of Munster. Around that time (in either 581 or 583) the Ossorians (also referred to in the Fragmentary Annals as Clann Connla) had slain one of the last usurping Corcu Loígde kings Feradach Finn mac Duach and reclaimed most of their old patrimony. The Dál Birn returned to full power by the first quarter of the seventh century. Throughout this period, Ireland and Irish culture was thoroughly Christianized by the arrival of missionaries from Britain and the continent. Osraige appears to have seen a flourish of early Christian activity. Surviving hagiographic works, especially those relating to St. Ciarán of Saighir, attest that Osraige was the first Irish kingdom to receive a Christian episcopacy even before the arrival of St. Patrick; however, some