The kingdom of Dál Riata was situated in modern Argyll and Bute, Scotland, and parts of County Antrim, Ireland.
The Irish annals record Áedán's campaigns against his neighbours, in Ireland, and in northern Britain, including expeditions to the Orkney Islands, the Isle of Man, and the east coast of Scotland.
The surviving Irish annals contain elements of a chronicle kept at Iona from the middle of the 7th century onwards so that these too are retrospective when dealing with Áedán's time.
In this story, Áedán is the twin brother of Brandub mac Echach, a King of Leinster who belonged to the Uí Cheinnselaig kindred.
"[2] Francis John Byrne suggested that the Echtra was written by a poet at the court of Diarmait mac Maíl na mBó, an 11th-century descendant of Brandub, and was written to cement an alliance between Diarmait and the Scots king Máel Coluim mac Donnchada ("Malcolm III"), who claimed to be a descendant of Áedán.
[3] A lost Irish tale, Echtra Áedáin mac Gabráin (The Adventures of Áedán son of Gabrán), appears in a list of works, but its contents are unknown.
[4] Áedán is a character in the epic Scéla Cano meic Gartnáin, but the events which inspired the tale appear to have taken place in the middle of the 7th century.
He may have earned this epithet after the collapse of an alliance with Rhydderch Hael, king of the nearby Brittonic kingdom of Alt Clut; the enmity between them is remembered in the Welsh Triads and elsewhere.
The Bonedd Gwŷr y Gogledd records him as a descendant of Dyfnwal Hen of Alt Clut, though the genealogy is much confused (Gauran is given as his son, rather than father).
According to the Senchus, Dál Riata was divided into three sub-kingdoms in the 7th century, each ruled by a kin group named for their eponymous founder.
Looking outward, Dál Riata's neighbours in north Britain were the Picts and the Britons of the Hen Ogledd, the Brittonic-speaking parts of what is now Northern England and southern Lowland Scotland.
Of the Uí Néill kings, Áed mac Ainmuirech of the Cenél Conaill, Columba's first cousin once removed, was the most important during Áedán's reign.
[15] Adomnán, the Senchus fer n-Alban and the Irish annals record Áedán as a son of Gabrán mac Domangairt (died c. 555–560).
"[24] In 575, the Annals of Ulster report "the great convention of Druim Cett", at Mullagh or Daisy Hill near Limavady, with Áed mac Ainmuirech and Columba in attendance.
[34] A number of Welsh traditions point to warfare between Áedán and King Rhydderch Hael of Alt Clut, the northern Brittonic kingdom later known as Strathclyde.
Hector Munro Chadwick and subsequent historians suggest Áedán was initially in a long-term alliance with Rhydderch and his predecessors, but that it eventually collapsed into conflict.
[8] Adomnán reports that Rhydderch sent a monk named Luigbe to Iona to speak with Columba "for he wanted to learn whether he would be slaughtered by his enemies or not".
The Irish poem Compert Mongáin says that the king of Ulster, Fiachnae mac Báetáin of the Dál nAraidi, aided Áedán against the Saxons, perhaps at Degsastan.
The Anglo-Saxon Chronicle mentions that Hering, son of King Hussa of Bernicia, was present, apparently fighting with Áedán.
[38] After the defeat of Degsastan, the annals report nothing of Áedán until his death around six years later, perhaps on 17 April 609, the date supplied by the Martyrology of Tallaght, composed c. 800.
[41] Áedán's other sons are named by the Senchus fer n-Alban as Eochaid Find, Tuathal, Bran, Baithéne, Conaing, and Gartnait.