A linguistic archipelago
The Caucasus Mountains are a "shatter zone," a region of extreme political and cultural fragmentation. Here, the fragmentation is linguistic. More than 50 distinct ethnic groups reside in this area, which is roughly the size of Spain. The deep valleys and high peaks created pockets of isolation, allowing languages to evolve independently over millennia. This intense geographical separation is the main reason for the region's unmatched linguistic density.
The indigenous languages fall into three main families that have no clear relation to each other: Kartvelian (South Caucasian), Northwest Caucasian (Abkhazo-Adyghean), and Northeast Caucasian (Nakh-Dagestanian). This is not a single "Caucasian" language family; the groups are as different from one another as they are from English or Mandarin. The region also contains languages from the Indo-European, Turkic, and Semitic families, introduced through historical migrations and conquests. Despite centuries of influence from Persian, Ottoman, and Russian empires, the core linguistic diversity of the Caucasus has persisted. The Republic of Dagestan in Russia is the most linguistically varied part of the region, home to about 30 indigenous ethnic groups.
Towers of consonants
Caucasian languages have a wide range of sounds. The Northwest Caucasian family is famous for its large consonant inventories. For instance, the now-extinct Ubykh language possessed at least 80 distinct consonants but only two or three vowels. This creates a phonetic structure alien to most of the world's languages. Many Caucasian languages also feature ejective consonants—sounds made with a burst of air from a closed glottis—which are rare globally.
Grammatically, these languages are highly complex. Most are agglutinative, they string together many morphemes to form single, long words. Many also use an ergative-absolutive case system, where the subject of an intransitive verb is treated the same as the object of a transitive verb, a system different from the nominative-accusative structure of English. While some languages like Georgian have a literary tradition stretching back to the 5th century AD, many others have never been written down. The Georgian nation, composed of speakers of Kartvelian languages, numbered around 4.2 million in the mid-1990s.