The Picts were a mysterious warrior people of ancient Britain. According to tradition, the Picts migrated from the shores of Brittany around the 15th century BC. They sailed northward to Ireland, but were refused permission to settle there by the ancient kings of that land. However, the Picts were granted permission to settle in the northeastern part of Scotland on the condition that each Pictish king marry an Irish princess, thus providing the Irish with a colony whose rulers were of royal Irish blood. This Pictish settlement was ruled by a matriarchal hierarchy unlike any other form of government in British history.

The Picts were noted for their ferocious resistance to the incorporation of Britain into the Roman Empire. The Romans gave the Picts the name by which we know them, and their name for themselves is now lost. The name Pict is derived from the Latin word pictus, which means painted, and refers to the designs painted by fierce Pictish warriors upon their bodies. The Picts and their rivals to the west, the Dalriadan Scots, relentlessly harried the Roman legions in Britain, leading to the construction of Hadrian's Wall as a defence against their raids. Nevertheless, even this barrier could not protect the Romans. The Picts and Scots overran the wall in 367 AD and slew a prominent Roman military commander.

Following the withdrawal of the Roman legions during the 4th century, the dramatic history of the Picts and their intense rivalry with the other tribes of Britain continued. The Pictish king Nechtan, who was recorded around 724 AD, was overthrown by Alpin, the product of a political marriage who had both Pictish and Dalriadan blood in his veins. His son, Kenneth Mac Alpin united Scotland after a victory over the Picts and became the first king of that nation. The Picts themselves were further compressed by the invasion of the Orcadian Vikings from the north, and were left with a territory stretching from Inverness to Edinburgh on the east coast of Scotland.