The Picts were a group of Late Iron Age (200 BC-400 AD) and Early Medieval (400-900 AD) Celtic people living in ancient eastern and northern Scotland. Picts are recorded from before the Roman conquest of Britain until the 10th century, when they merged with the Gaels. They are assumed to have been the descendants of the Caledonii and other tribes named by Roman historians. Pictland, also known as Pictavia, gradually merged with the Gaelic kingdom of Dál Riata (a Gaelic overkingdom on the western coast of Scotland and on the northeast coast of Ireland) to form the Kingdom of Alba (Scotland, 900-1286 AD).
Find out more in Wikipedia http://en.wikipedia.org/wiki/Picts
Below a short film by David Mudie about Picts for the Pictavia Museum in Brechin (Angus council area, SCOTLAND).