The two great Southern Uí Néill dynasties of the midlands were the Síl nÁedo Sláine (the Seed of Áedo of Slane), kings of Brega in the east, and the Clann Cholmáin Máir (the Children of Colmán the Great) in Mide with their centre in the heart of modern Westmeath.
The former are more prominent in the seventh century, but after the death of Cináed mac Írgalaig in 728 all the high-kings of the Southern Uí Néill come from the Clann Cholmáin except for a brief period between 944 and 956 when the king of Knowth, Congalach Cnogba, restored the high-kingship to the Brega line.
Compared to his father and his sons, relatively little is said of Áed, either in the Irish annals or in other sources such as hagiography or heroic verse.
In 600 Áed had his nephew, Suibne mac Colmáin Már, killed, "treacherously" says Adomnán.
Colmán was murdered by a kinsman and Suibne's son Conall Guthbinn killed Áed.
Áed's recorded children are at least six sons, including Diarmait and Blathmac, and a daughter named Rontud.