According to the traditional account, he inherited the throne of Dál Riada from his father Alpín mac Echdach, founder of the Alpínid dynasty.

Forteviot became the capital of his kingdom and Kenneth relocated relics, including the Stone of Scone from an abandoned abbey on Iona, to his new domain.

Kenneth I is traditionally considered the founder of Scotland, which was then known as Alba in Gaelic, although like his immediate successors, he bore the title of King of the Picts.

It was Donald II that first bore the title of King of Alba as recorded by the Annals of Ulster and the Chronicon Scotorum.

Alpín is considered to be the grandson of Áed Find, a descendant of Cenél nGabráin, who ruled in Dál Riada.

[b] Modern historians are sceptical about the reign of Alpín in Dál Riada and his relationship with Áed, and believe this misconception is the result of negligence on the part of the scribes in some texts.

[2][3] The genealogy of the kings of Scotland and Dál Riada dates back to an original manuscript that was written during the reign of Malcolm III in the mid-to-late 11th century.

[3][6] Although some sources state Kenneth ruled the Picts from 841 to 856, according to the Chronicle of Melrose, he became king in 843, a date that is generally accepted by most modern-day historians.

Kenneth's realm lay between the powerful Kingdom of Strathclyde in the south and the Druim Alban mountain ridge in the east.

[d] No chronicle mentions either Kenneth's continuing his father's campaign against the Picts or his supposed claim to the Pictish crown.

It is likely the death of Eógananhe, Chronicle of Huntingdon gives the following interpretation of the events that took place after Eóganan's death: Kynadius [Kenneth] succeeded his father Alpin in his kingdom, and that in the seventh year of his reign [the year 839], while the Danish pirates, having occupied the Pictish shores, had crushed the Picts, who were defending themselves, with a great slaughter, Kynadius, passing into their remaining territories, turned his arms against them, and having slain many, compelled them to take flight, and was the first king of the Scots who acquired the monarchy of the whole of Alban, and ruled in it over the Scots.

[3][9][17] After the conquest of Pictavia, the Scots from Dál Riada began to migrate en masse to the territories populated by the Picts.

Kenneth moved relics from an abandoned abbey on Iona, where Viking raids made life untenable, to Dunkeld, which was the centre of the Church of Scotland, in 848 or 849, according to the Chronicle of the Kings of Alba.

According to archaeological excavations, Forteviot was probably originally a royal residence but the place is not mentioned in the chronicles after the death of Donald I.

[3][19] Kenneth strengthened his power by arranging royal marriages with neighbouring states, marrying his daughters to the kings of Strathclyde and Ireland.

Succession in the kingdom was carried out in the form of tanistry so Kenneth's successor was his brother Donald I rather than his eldest son.

It is possible the use of the title of King of the Picts was in reference to Kenneth and his immediate successors' claim to all of Pictavia, though there is very little evidence of the extent of their domain.