This sept had their royal seat at Maistiu (Mullaghmast) in South Kildare.
In 814 Muiredach and Cellach won a victory over the Uí Cheinnselaig of south Leinster.
[3] Common hostility to Kildare may show that Cellach was in sympathy with Feidlimid mac Cremthanin (died 847) of Munster for political or religious reasons.
[4] In 831 the men of Laigin had joined Feidlimid in a campaign that plundered Brega.
That same year the high king Conchobar mac Donnchada (died 833) of Clann Cholmáin plundered the Liffey in retaliation.