Cinaeth, known to history as Kenneth MacAlpin or Kenneth the Hardy, was born around 810 on the Island of Iona. He was the son of the Scots chieftain Alpin, who had lead his countrymen in the struggle against the Picts and the invading Vikings. Alpin, the son of Eochaid the Venomous, was an obscure character but tradition states that he won a victory over the Picts, who later killed him, displaying his severed head in their camp.
Following the death of his father, Kenneth took up his standard and occupied the Pictish strongholds of Fortriu and Forteviot in Perthshire.
The Picts, reputed to be fierce warriors, were engaged in fighting the invading Vikings, who had previously killed the Pictish king, Eagan. Following victory in battle Kenneth became accepted as King of the Picts also. He was made King on the Moot Hill at Scone, (pronounced skoon) seated upon the famous Stone of Scone. The stone's origins are obscured by the mists of time, but it was probably brought to Argyll from Antrim by Fergus MacErc of the Dal Riata Gaels. It's Gaelic name was Lia Fail meaning the speaking stone. Scone itself was seen as the sacred centre of Pictavia.
At a banquet at Scone, Kenneth murdered the seven Earls of the Scot's kingdom of Dalriada, who might have lead opposition to his claim to be King of Scots and Picts, marking what was hoped to be the end of the conflict. The murder is popularly known as MacAlpin's treason.
Although his father Alpin had been a Dalraid Scot, Kenneth had a Pictish mother and since the Pictish law of inheritance passed through the Matrilineal line, he also claimed to be the rightful representative of the Pictish line of Kings. Kenneth married the daughter of his second cousin, Constantine.
Kenneth itself was a Pictish name. The name Picts had been coined by the Romans, who referred to the inhabitants of Scotland as Picti or painted men, due to their practice of dying their bodies with woad before going into battle. The Pictish language and culture was gradually taken over by that of the Scots.
Kenneth I sought repeatedly to conquer the Angles of Lothian, but did not meet with success in this area. He engaged in a long war against the Bernicans, who themselves were struggling against the Viking threat, crossing the Forth, then the boundary between the two countries, burning and looting Saxon villages, but made no significant territorial gains. The first King of Scots placed his capital at Dunkeld in Perthshire, he also transferred of some of St. Columba's relics from Iona.
After a seventeen year reign Kenneth I died at Forteviot, Perthshire, possibly of cancer, he was buried on the island of Iona. He was succeeded by his younger brother, Donald I, in accordance with the tanist system of inheritance. The Picts and their bards lamented his passing-
'That Kenneth with his host is no more brings weeping to every home. No king of his worth under heaven is there, to the bounds of Rome.'
Kenneth left at least two sons, Constantine and Áohd, who were later kings of Scotland and two daughters. One of his daughters married Run, king of Strathclyde, Eochaid, wo later ruled Scotland was the son of this marriage. Kenneth's daughter Máel Muire married firsly to Aed Finliath of the Cenél nEógain, an Irish king of the Uí Néill. Niall Glúndub, ancestor of the O'Neill, was born of the marriage. Her second husband was Flann Sinna of Clann Cholmáin. When Máel Muire died in 913, her death was recorded in the Annals of Ulster.