Derelitius, Chief of the North Picts

The Picts were a tribal confederation of peoples who lived in eastern and northern Scotland during the Late Iron Age and Early Medieval periods.[1] They are thought to have been ethnolinguistically Celtic. The place where they lived and what their culture was like can be inferred from the geographical distribution of brochs, Brittonic place name elements, and Pictish stones. Picts are attested to in written records from before the Roman conquest of Britain to the 10th century, when they are thought to have merged with the Gaels. They lived to the north of the rivers Forth and Clyde, and spoke the now-extinct Pictish language, which is thought to have been related to the Brittonic language spoken by the Britons who lived to the south of them. Picts are assumed to have been the descendants of the Caledonii and other tribes that were mentioned by Roman historians or on the world map of Ptolemy. Pictland, also called Pictavia by some sources, gradually merged with the Gaelic kingdom of Dál Riata to form the Kingdom of Alba (Scotland). Alba then expanded, absorbing the Brittonic kingdom of Strathclyde and Bernician Lothian, and by the 11th century the Pictish identity had been subsumed into the "Scots" amalgamation of peoples. Pictish society was typical of many Iron Age societies in northern Europe, having "wide connections and parallels" with neighbouring groups.[2] Archaeology gives some impression of the society of the Picts. While very little in the way of Pictish writing has survived, Pictish history since the late 6th century is known from a variety of sources, including Bede's Historia ecclesiastica gentis Anglorum, saints' lives such as that of Columba by Adomnán, and various Irish annals.

http://en.wikipedia.org/wiki/Picts