The Picts were ancient inhabitants of Scotland whose forebears probably came from the European continent around 1000 B.C.  Their confederation of tribes in northern Scotland eventually ran from Fife to Caithness. The Picts were in general agrarian living in small communities, similar in culture to most other celts including Pagan animistic polytheism. In 843 A.D. they united with the kingdom of the Scots and were assimilated into the Scottish nation.
Writing & Language
The Picts had their own system of writing, Pictish. However, little survives today, so the history of the Picts themselves is a largely "academically recreated" history from other sources. The language, Pictish, is generally regarded as an Insular Celtic language, but this is based only on remaining evidence such as place names.
In battle, the Picts used to dye their faces and skin with blue woad, giving them a fearsome appearance.
The New American Desk Encyclopedia, Penguin Group, 1989