Colchis is the birth country of Medea, where Jason and the Argonauts sailed to capture the Golden Fleece. It is located between the Caucasus Mountains and the eastern edge of the Black Sea and is at the border between Europe and Asia.
Colchis was colonized by Milesian Greeks and had a population whose tribes are labeled 'Colchi', 'Heniochi', and 'Lazi'. It was part of the Achaemenid Persian Empire and then part of the Hellenistic Seleucids at which time it lost territory to its neighbor Iberia. Rome acquired Colchis under the Emperor Nero in 64, when Colchis became part of the province of Cappadocia.
Source: David C. Braund "Colchis" The Oxford Classical Dictionary. Simon Hornblower and Anthony Spawforth. © Oxford University Press 1949, 1970, 1996, 2005.