Áedán mac Gabráin
Áedán mac Gabráin or Áedan of Dalriada was the first king of Scotland that historians know lived in real life.  He was not only a legend or myth.  Stories say he was the son of King Gabhran mac Domangairt. Aedan's son, Eochaid Buide, became king after him in the early sixth century. He ascended the throne in the 570s. One source says Aedan died in 608.