Tsakonian or Tsaconian (also Tzakonian or Tsakonic, τσακώνικα and Tsakonian: τσακώνικα, α τσακώνικα γρούσσα) is a highly divergent modern variety of Greek, spoken in the Tsakonian region of the Peloponnese, Greece. Tsakonian derives from Doric Greek, being its only extant variant. Although it is conventionally treated as a dialect of Greek, some compendia treat it as a separate language.
Tsakonian is critically endangered, with only a few hundred/thousand, mostly elderly, fluent speakers left. Although Tsakonian and standard Modern Greek are related, they are not mutually intelligible.
The term Tsakonas or Tzakonas first emerges in the writings of Byzantine chroniclers who derive the ethnonym from a corruption of Lakonas, a Laconian/Lacedaemonian (Spartan)—a reference to the Doric roots of the Tsakonian language.
Tsakonian is found today in a group of mountain towns and villages slightly inland from the Argolic Gulf, although it was once spoken farther to the south and west as well as on the coasts of Laconia (ancient Sparta).
Geographical barriers to travel and communication kept the Tsakonians relatively isolated from the rest of Greece until the 19th century, although there was some trade between the coastal towns. The rise of mass education and improved travel beginning after the Greek War of Independence meant that fluent Tsakonian speakers were no longer as isolated from the rest of Greece. In addition, during the war, the Turkish army drove the Tsakonians east, and as a result, their de facto capital shifted from Prastos to Leonidio, further making the people significantly less isolated. There began a rapid decline from an estimated figure of some 200,000 fluent speakers to the present estimate of a speaker count between 200 and 1,000.
Since the introduction of electricity to all villages in Tsakonia by the late 1950s, Greek mass media can reach the most remote of areas and has profoundly affected the speech of younger speakers. Efforts to revive the language by teaching it in local schools do not seem to have had much success.