Sir William Jones discovered in the late 18th century that Sanskrit, Latin, Greek and other European languages were related and derived from a common ancestral language now called Proto-Indo-European. The Celts were the first Indo-European speakers in Europe. In the 5th century AD, Germanic tribes like the Angles, Saxons and Jutes invaded Britain, displacing some Celtic Britons and introducing Old English, an early form of the language derived from various Germanic dialects. Old English was spoken from the 5th to 12th centuries in England and southern Scotland and incorporated few Celtic or Latin words despite those languages being present in Britain.