Amalgaid mac Congalaig (died 718) was a King of Brega from the Uí Chonaing sept of Cnogba (Knowth) of the Síl nÁedo Sláine branch of the southern Ui Neill.
[4] The high king Fergal mac Máele Dúin (died 722) of the Cenél nEógain seems to have favored Clann Cholmáin in Meath and intervened in the affairs of the midlands.
[5] In 711, the Battle of Sliab Fúait (in the Fews, Co. Armagh) is recorded where Fergal was victorious and Cú Raí mac Áedo of Síl nDlúthaig was slain along with the king of Uí Méith.
[6] In 714, Fergal's southern deputy Murchad Midi (died 715) of Uisnech fought the Battle of Bile Tened (Billywood, Co. Meath) where Amalgaid's ally Flann was slain.
Amalgaid and his brother Fergal were slain along with their allies, Gormgal mac Áedo of Síl nDlúthaig and Tuathal Ua Fáelchon of Clann Cholmáin Bicc.