The northern edge of the region follows the crests of the Great Caucasus Mountains from the Black Sea eastward to near the Caspian Sea. At that point the mountain line crosses northeastern Azerbaijan and dwindles to the Abseron Peninsula, leaving a triangle of land north of the mountains. The northern wall has only two easy passes: one along the Caspian Sea, and the other the long fortified Darya Pass in Georgia, the famous Iberian Gate(5). The Lesser Caucasus Mountains start at the regional border but soon cross south central Georgia. From there they mark the Armenian-Azerbaijani border pointing southeast towards the highlands of Iranian Azerbaijan(6). The Kura(7) River system dominates the intermontane plains. The south center of the region is comprised of highlands surrounding Lake Sevan. Several mountains in the east top 4000 meters including Bazarduzu in northeast Azerbaijan and Aracag west of Lake Sevan. Along the Georgian/ Russian border are some over 5000 meters including Schara and Kazbek.
Most people live in the lowlands and speak three languages: Azeri(8) in Azerbaijan, Armenian(9) in Armenia, and Georgian(10) in Georgia. This generalization disguises an amazing linguistic diversity, much of it with thousands of years of local history, tucked into mountain valleys, and adding in total to a substantial minority of the region. But the fourth largest language is not an ancient one, but a new comer: Russian, spoken by about one in twenty. And Talyish, an Iranian language, while it may have been in the area for one or two millenia, is a relative newcomer, and also accounts for about one in twenty. Two religions account for almost everyone: Islam and Christianity. Azerbaijanis are more than 80%(11) Sunni Moslems, Armenians overwhelmingly Armenian Orthodox Christian and the Georgian majority is Georgian Orthodox Christian. There are also substantial numbers of Russian Orthodox Christians. The three capitals represent the three largest cities: Baku(12) sits on the south shore of the Abseron Peninsula; Jerevan is southwest of the lake and near a tributary of the Aras River; and Tbilisi is on the Kura itself, sprawling lengthwise along the riparian banks.
The northwest corner has probably been Abkhaz and Mingrelian speaking for thousands of years, with the exception of a Greek speaking colony that flourished at modern Sukhumi in the first millinium BCE. Most of these people fled to Turkey in 1864 when Russia conquered the area and persecuted Moslems. One of the many former names of Georgia was Lazica, which may indicate that Laz speakers once predominated, at least in the southwest, but they are mostly in Turkey today. Further east in the area classically known as Iberia, Georgians have probably also been around for thousands of years; they converted to Christianity in the fourth or fifth century. Armenians adapted that religion about the same time but they are comparative new comers(13); in the first millenium BCE they displaced the Urartu who had probably been there for longer than their nation and history(14). Azeri speakers are the newest of the national groups. Their ancesters spoke the language that fathered Turkmen, Azeri and Turkish, and they arrived from the north between the seventh and 11th centuries, later converting to Islam. The politically eminent groups before that spoke Iranian languages but it is difficult to piece together which ones. This much is known: I. Speakers of Proto-Iranian lived north of the region and some of them moved through the region to Iran and beyond. II. The prophet Zoroaster is said to have lived in the first millenium BCE in today's Azerbaijan. He wrote in Avestan, a language little removed from Proto-Iranian(15). III. The Medes, speakers of a lost Iranian language lived in north west Iran--judging from toponyms--and at the least--also had political influence in the area's southeast during the middle of the first millenium BCE. IV. The Persian kingdom of Atropane(16) was founded in the fourth century BCE where Azeris now live and after which the language and land are named. In any case it was long connected with Persia or Persians and converted to Shiite Islam along with the population to the south. I don't know whether the ancesters of the Azeris converted to Sunni Islam before or after their invasion.
north
northeast across the Caspian Sea from northeast Azerbaijan
east, across the Caspian Sea
southeast of Azerbaijan
south
southwest
west
(1) Sakartvelo in Georgian.
(2) Transliterated from the Azari as Azarbaycan.
(3) Hayastan in Armenian.
(4) The region as a whole is sometimes called Transcaucasia.
(5) Also known as the Caucasian Gate and the Tatar Gate.
(6) Azarbaijan in transliterated Persian.
(7) Kur in Azeri, Kura in Georgian.
(8) Not to be confused with Azari.
(9) Hai in Armenian.
(10) The national dialect is called K'art'li.
(11) Estimates range from 82 to 93%.
(12) Also known as Baki.
(13) Probably arriving from the northwest.
(14) They spoke what was probably a North East Caucasian language. Urartu was not their name for themselves.
(15) It has survived only in holy texts which have traditional, but inaccurate, translations.
(16) Its Greek name.