According to legend , Achaius , King of Scots -LRB- possibly coming to the aid of Óengus mac PERSON@1 , King of the Picts -RRB- , while engaged in battle at LOCATION@1 with the Saxon King Aethelstan of LOCATION@2 , saw in the heavens the cross of St Andrew .

One story says that Achaius , ORGANIZATION@1 , was fighting King Aethelstan of LOCATION@2 and he saw cross of St Andrew in the sky .
