Constantine mac Áed (Constantine II), the grandson of Kenneth MacAlpin, began his life as an exile. In 878 AD his father, Áed, had been slain by a Giric, son of Dungal, and Constantine, a young boy at the time, fled to Ireland where he was brought up by monks surrounded in Gaelic culture.
In 889 AD he returned with his cousin Donald to wreak revenge on Giric. Donald took the kingship of the Picts initially, but shortly afterwards was slain by the Vikings – Dark Age kingships were often painfully short! So it was that in his early twenties, Constantine mac Áed became King of Pictland.
The kingdom had been nearly destroyed by the Vikings, but its peoples, Picts and Gael, faced with the prospect of Viking conquest, had drawn together. In 902 AD, the Vikings, under Ivar the Younger of Dublin, returned to seize Dunkeld, where St Columba's relics were kept, and the rich farmlands around the River Tay. Constantine caught up with Ivar at Strathcarron in 904 AD, and, in a bitter struggle, Ivar and his Viking army were massacred.
With the defeat of the Vikings, regeneration of the kingdom was Constantine's top priority. He remodelled the church along Gaelic lines and brought in a system of mormaers (earls) to defend the kingdom more efficiently. He also renamed the territory, Alba, which is actually means Britain in Gaelic. Pictland was remade in a Gaelic image and the Scottish nation was launched.
Constantine continued to extend Alba's influence across Scotland. The east coast, south of the river Forth and modern-day Edinburgh, was Angle territory and often very hostile at that, until 918 AD, when Constantine led his army into Northumbria. At the Battle of Corbridge, he forced Ragnall, the Viking King of York, to withdraw from the Angle earldom of Northumbria that stretched from Lothian to the Tyne.
In return the restored earl, Eadred, recognised Constantine as his overlord. For the first time much of the land in modern-day Scotland was either under the direct kingship of the King of Alba or was under his rule as overlord.
The power of the pagan Vikings began to wane in the early 10th century as Christian kings like Constantine and the Kings of Wessex allied against them. In 928 AD, Aethelstan, the Anglo-Saxon King of Wessex, conquered the Viking Kingdom of York. Not content to stop there, he aimed for nothing less than subduing the whole of Britain to his will.
In 934 AD Aethelstan marched north, forcing the Earls of Northumbria and the Kings of Strathclyde to acknowledge him as overlord. Alba had never seen so vast an army: Aethelstan had brought with him three Welsh kings and six Viking chieftains.
Constantine was forced into retreat and was besieged, it is thought, at the rock fortress of Dunnottar. The fortress was too strong for Aethelstan to take, however Constantine must have been forced into some form of recognition of Aethelstan's claims.
Constantine's response to Aethelstan came in the form of cunning diplomacy. He married his daughter to Olaf Guthfrithsson, the pagan king of Viking Dublin and persuaded Owein of Strathclyde, his relative, to support his cause.
In 937 AD they invaded Aethelstan's England. At the Battle of Brunanburh, at an unknown location deep in England, they fought one of the largest and bloodiest battles of the Dark Ages. Aethelstan was victorious, Owein of Strathclyde was killed and the Anglo Saxon Chronicle revelled in Constantine's defeat.
"The hoary man of war had no cause to exult in the clash of blades; he was shorn of his kinsmen, deprived of friends, on the meeting place of peoples, cut off in strife, and left his son on the place of slaughter, mangled by wounds, young in battle. The grey-haired warrior, old crafty one, had no cause to boast"
Despite defeat, Aethelstan was weakened and Constantine's diplomacy and network of allies had freed Alba and Strathclyde from the southern threat. Olaf Guthfrithsson restored Viking rule to York and Aethelstan's grand schemes lay in ruins.
In 943 AD, after reigning for 43 years, Constantine retired from the kingship and for the final nine years of his life became a monk at St Andrews.
He was Scotland's most successful Dark Age king, a success won through a combination of strength in battle and diplomacy. His combined forces approximated something very close to a northern powerblock, one which pitted itself against another powerblock to the south – a story which was to repeat itself many times throughout the next millennium.