 Later Uí Cheinnselaig kings, such as Diarmait mac Mail na mBo and his grandson Diarmait mac Murchada, although descended from a different line, associated Brandub's successes with their branch of the clan.In 605 Brandub suffered a defeat at the Battle of Slaebre by the Ui Neill under the high king Áed Uaridnach of the Cenél nEógain.He was then assassinated by his own kinsman and son-in-law Sarán Saebderc.