King Æthelstan of England secured the submission of four northern rulers: Constantine II of Scotland, Hywel Dda of Deheubarth, Ealdred I of Bamburgh, and Owain ap Dyfnwal of Strathclyde, leading to seven years of peace.

Æthelstan or Athelstan was King of the Anglo-Saxons from 924 to 927 and King of the English from 927 to his death in 939. He was the son of King Edward the Elder and his first wife, Ecgwynn. Modern historians regard him as the first King of England and one of the "greatest Anglo-Saxon kings". He never married and had no children; he was succeeded by his half-brother, Edmund I.

Causantín mac Áeda was an early King of Scotland, known then by the Gaelic name Alba. The Kingdom of Alba, a name which first appears in Constantine's lifetime, was situated in what is now Northern Scotland.

Hywel ap Cadell, commonly known as Hywel Dda, which translates to Howel the Good in English, was a Welsh king who ruled the southern Welsh kingdom of Deheubarth and eventually came to rule most of Wales. He became the sole king of Seisyllwg in 920 and shortly thereafter established Deheubarth, and proceeded to gain control over the entire country from Prestatyn to Pembroke. As a grandson of Rhodri Mawr through his father Cadell, Hywel was a member of the Dinefwr branch of the dynasty. He was recorded as King of the Britons in the Annales Cambriæ and the Annals of Ulster.

Ealdred was a ruler of Bamburgh, at least part of the former kingdom of Bernicia in northern Northumbria, in the early tenth century. He was the son of Eadwulf.

Owain ap Dyfnwal was an early tenth-century King of Strathclyde. He was probably a son of Dyfnwal, King of Strathclyde, who may have been related to previous rulers of the Kingdom of Strathclyde. Originally centred in the valley of the River Clyde, this realm appears to have undergone considerable southward expansion in the ninth or tenth century, after which it increasingly came to be known as the Kingdom of Cumbria.