As far back as the 16th century scholars commented on similarities among the oldest known languages – especially Sanskrit, Greek, and Latin. By the mid 17th century they began to argue for a common mother tongue from which many modern, and many extinct, languages had descended. Serious work was done in the 18th and 19th centuries, so that the notion of a mother tongue became the standard assumption. By studying the systematic sound changes that occurred among languages, scholars were able to widen the extent of descendants of this mother tongue, which came to be called Proto-Indo-European (PIE). They were also able to reconstruct what were the most likely sounds and senses of various word roots in PIE as well as some of its morphological and grammatical processes.
PIE is assumed to have been spoken around 5000 BC in an area north of the Black and Caspian Seas in what today would be southwestern Russia. Over time the Proto-Indo-Europeans dispersed – to the east as far as central Asia and India, to the north as far as northern Europe, including Scandinavia, to the south to Persia, and to the west through Greece, Italy, and throughout western Europe. As the diaspora went on, the core of PIE language tended to remain, but with marked, usually systematic changes brought on by separation from other PIE speakers and by interaction with the indigenous languages of the various regions into which PIE moved.
Today the Indo-European superfamily consists of well over 400 languages with more than three billion native speakers. Today it continues to spread – especially via the spread of English to areas like South Africa and Australia, and as English becomes an increasingly wide-spread international language – as, for instance, in airline communication and international commerce. For a somewhat simplified family tree of PIE’s descendants click on The Indo-European Family.
David W. Anthony. The Horse, the Wheel, and Language: How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World . Princeton and Oxford: Princeton University Press, 2007
Winfred P. Lehmann. Theoretical Bases of Indo-European Linguistics . London and New York: Routledge,1993
J. P. Mallory. In Search of the Indo-Europeans: Language, Archaeology and Myth . London: Thames and Hudson, 1989
Colin Renfrew. Archaeology and Language: The Puzzle of Indo-European Origins . Cambridge and NY: Cambridge University Press, 1987
Calvert Watkins. "Indo-European and the Indo-Europeans" in his
The American Heritage Dictionary of Indo-European Roots, 2nd edn.
Boston and New York: Houghton Mifflin, 2000