The inclusion of Pictish kings from Caustantín to Eogán in the Duan led to the supposition that Dál Riata was ruled by Pictish kings, or rather that Dál Riata kings ruled Pictland, leading to supposition that the origins of the Kingdom of Alba lay in a Gaelic conquest of Pictland.
Óengus II (before 780–834), king of Picts, a/k/a Onuist, Hungus or Angus, from 820 until 834, traditionally associated with cult of Saint Andrew and flag of Scotland; included in Duan Albanach's praise poem from reign of Máel Coluim
Óengus II | Óengus mac Nad Froích | Óengus mac Fergusa | Óengus I |
On the eve of a battle between an army of the Picts and invading Angles from Northumbria in 832AD, Saint Andrew, who was crucified on a diagonal cross, came to the Pictish King Óengus II in a vision promising victory.