Its population, the Colchians, are generally thought to have been mainly an early Kartvelian-speaking tribe ancestral to contemporary western Georgians, namely Svans and Zans.

[6] According to David Marshall Lang: "one of the most important elements in the modern Georgian nation, the Colchians were probably established in the Caucasus by the Middle Bronze Age.

[36] According to Donald Rayfield, the ethnic makeup of Colchis is "obscure" and Kartvelian names "are conspicuously absent from the few anthronyms found in Colchian burials.

Earlier writers speak of the "Kolchian" (Κολχίδα) people and their mythical king Aeëtes (Αἰήτης), as well as his eponymous city Aea or Aia (Αἶα),[44][45][46] but don't make explicit references to a Kolchis nation or region.

The main river was known as the Phasis (now Rioni) and was, according to some writers the southern boundary of Colchis, but more probably flowed through the middle of that country from the Caucasus west into the Euxine, and the Anticites or Atticitus (now Kuban).

Arrian mentions many others by name, but they would seem to have been little more than mountain torrents: the most important of them were Charieis, Chobus or Cobus, Singames, Tarsuras, Hippus, Astelephus, Chrysorrhoas, several of which are also noticed by Ptolemy and Pliny.

The chief towns were Dioscurias or Dioscuris (under the Romans called Sebastopolis, now Sukhumi) on the seaboard of the Euxine, Sarapana (now Shorapani), Phasis (now Poti), Pityus (now Pitsunda), Apsaros (now Gonio), Surium (now Vani), Archaeopolis (now Nokalakevi), Macheiresis, and Cyta or Cutatisium or Aia (now Kutaisi), the traditional birthplace of Medea.

The central part of the region is Colchis Plain, stretching between Sukhumi and Kobuleti; most of that lies on the elevation below 20 m (66 ft) above sea level.

[citation needed] The climate is mild humid; near Batumi, annual rainfall level reaches 4,000 mm (160 in), which is the absolute maximum for continental western Eurasia.

[citation needed] Colchis has a high proportion of Neogene and Palaeogene relict plants and animals, with the closest relatives in distant parts of the world: five species of Rhododendrons and other evergreen shrubs, wingnuts, Caucasian salamander, Caucasian parsley frog, eight endemic species of lizards from the genus Darevskia, the Caucasus adder (Vipera kaznakovi), Robert's snow vole, and endemic cave shrimp.

The Colchian Late Bronze Age (fifteenth to eighth century BC) saw the development of significant skill in the smelting and casting of metals.

[50][51] Sophisticated farming implements were made, and fertile, well-watered lowlands and a mild climate promoted the growth of progressive agricultural techniques.

[12] According to Svante Cornell, "What could be conceived as the proto Georgian statehood emerged mainly in the Western parts of today's Georgia, with the kingdom of Colchis (Kolkheti) in the sixth century BC.

Chief among those were the Machelones, Heniochi, Zydretae, Lazi, Chalybes, Tibareni/Tubal, Mossynoeci, Macrones, Moschi, Marres, Apsilae, Abasci,[53] Sanigae, Coraxi, Coli, Melanchlaeni, Geloni and Soani (Suani).

The influence exerted on Colchis by the vast Achaemenid Empire with its thriving commerce and wide economic and commercial ties with other regions accelerated the socio-economic development of the Colchian land.

[65] According to David Braund's reading of Strabo's account, the native Colchian dynasty continued ruling the country in spite of its fragmentation into skeptoukhies.

[66] Gocha R. Tsetskhladze explains that although Colchis and neighboring Iberia were once viewed as not having been under Achaemenid rule, "ever more evidence is emerging to show that they were, forming a lesser part of the Armenian satrapy".

During the Third Mithridatic War, Mithridates VI made another of his sons, Machares, king of Bosporus and Colchis, who held his power, but only for a short period.

Phasis, Dioscurias and other Greek settlements of the coast did not fully recover after the wars of 60-40 BC and Trebizond became the economical and political centre of the region.

[70] Arrian listed the following peoples in his Periplus of the Euxine Sea written in 130-131 (from south to north): Sanni, Machelones, Heniochi, Zudreitae, Lazi, Apsilae, Abasgoi, Sanigs and Zilchi.

[71] According to traditional accounts Christianity began to spread in the early first century by Andrew the Apostle, Simon the Zealot, and Saint Matthias.

Here in the sacred grove of the war god Ares, King Aeëtes hung the Golden Fleece until it was seized by Jason and the Argonauts.

Colchis was also the land where the mythological Prometheus was punished by being chained to a mountain while an eagle ate at his liver for revealing to humanity the secret of fire.