Áed mac Colggen (died 738) was a king of theUí Cheinnselaig ofLeinster. Some sources incorrectly make him jointking of Leinster withBran Becc mac Murchada, but it appears that Áed was main ruler of Leinster in 738.[1] His father Colcú mac Bressail (died 722) was called king ofArd Ladrann (near Gorey, Co.Wexford) at his death obit in the annals in 722 which mention that he was killed.[2] He was the great-great grandson ofCrundmáel Erbuilc (died 656), a King of Leinster, and was a member of the Sil Chormaic sept.
The date of his succession to the Uí Cheinnselaig throne cannot be dated with certainty. The annals record that the Ui Cheinnselaig kingLaidcnén mac Con Mella was slain at the Battle of Maistiu (Mullaghmast in southCounty Kildare) in 727 by the Leinster kingDúnchad mac Murchado (died 728).[3] The king lists in theBook of Leinster, have him succeeded byÉlothach mac Fáelchon who ruled for seven years before being slain by Áed mac Colggen at the Battle of Oenbethi who then is listed as king.[4]
In 722 Leinster faced an invasion byFergal mac Máele Dúin of theCenél nEógain,High King of Ireland, seeking to impose his overlordship on Leinster. Their armies under the kingMurchad mac Brain Mut (d.727) met at the battle of Allen where Fergal was killed. The sagaCath Almaine preserves the story of this battle and mentions that Áed mac Colggen fought for Leinster where he is referred to as heir-apparent.[5]
Áed appears as a rival to the Leinster throne during the reign ofFáelán mac Murchado (died 738) at a time whenCathal mac Finguine (died 742), King ofMunster, was attempting to assert his rights over Leinster during a time of Uí Neill weakness.[6] In 732 Aed and the southern Laigin (Laigin Desgabair) repulsed the Munstermen.[7]
Áed, along with many other kings, was killed in battle against Fergal's sonÁed Allán atÁth Senaig in 738. This fight (known as the Battle of the Groans) is described at length in theIrish annals. Áed was slain in single combat with Áed Allán and his supposed co-ruler Bran Bec also died there. TheAnnals of Ulster say:[8]
And men say that so many fell in this great battle that we find no comparable slaughter in a single onslaught and fierce conflict throughout all preceding ages.
After the crushing defeat at Áth Senaig, theUí Dúnlainge dominated the kingship of Leinster for fully three centuries untilDiarmait mac Maíl na mBó became king of Leinster in 1042.[citation needed]
Aed was succeeded as king ofUí Chennselaig by his brotherSechnassach mac Colggen (died 746/747). Áed's sonEterscél mac Áeda (died 778) was later king of the Uí Cheinnselaig.[citation needed]