This is Bryan's clan

The O'Dananns cover much of the land between Raphoe and Doire, east of the Foyle River, in the relatively young kingdom of Tír Eóghain.  They have an old reputation as fearsome cattle raiders, which they occasionally renew to ensure that it is not forgotten.  Their rivalry with the Mac Lochlainn clan to their north goes back many generations.

The O'Dananns' reputation was marred when their previous clan king allowed a monastery that was under their protection to be sacked by Manx raiders.  He was quickly overthrown, and his family killed in the ensuing fighting or else exiled from the clan.  The current king, Treasach mac Dubhghall, hails from a different family line.  It remains to be seen if his efforts will repair their reputation in the eyes of the other clans.