When soviet power was finally established in central Asia in the early 1920s, the Bolsheviks' task was to establish central administrative control in the former czarist territories, and eliminate any possibility of cohesion among the various peoples of the region to oppose Moscow's authority.

A formula for collecting peoples of the same language was devised and adopted in 1924, and the four union republics of Kirghizia, Tadzhikistan, Turkmenia and Uzbekistan emerged.

In the years since, the Soviets have generally emphasized the separate nationalities, languages and histories of the republics, while at the same time establishing uniform education, health and medical standards.

The written language has been changed three times, from the traditional Arabic alphabet, to Latin script, to Cyrillic script with local special letters to accommodate spelling and pronuniciation variations.

Like the other 11 union republics, the central Asian republics have theoretical powers to pursue their own foreign policies, even raise armies or secede from the federation. In practice, these rights exist only on paper. The republics have their own unicameral legislatures and send delegates to the Supreme Soviet, which meets annually in Moscow.

The republics:

KIRGHIZIA: Eastermost, borders on Sinkiang, China. Capital: Frunze. Population in 1970: 2.9 million. About the size of South Dakota. Mixed economy of agriculture, dominated by cotton, vegetables, sheep, goats, and cotton, vegetables, sheep, goats, and catle, on the richest pastures in Central Asia. Industry of mining, mental-working and engineering. Kirghizis, the dominant minority, are Moslems, mostly pastoral, speak Turkish based language.

TADZHIKISTAN: Borders Afghanistan and Sinkiang across the Pamir Mountains. Capital: Dushanbe. Population in 1975: 3.4 million. About the size of Arkansas. Cotton, grain, animal husbandry, silk, apricot and raisins dominate in agriculture. Mining, cotton and silk processing are among major industries. The Tadzhiks number about 1.6 million in the republic, more than 500,000 in Uzbekistan and more than 5 million in Afghanistan. They speak Persian dialects and are Moslems (including Sunni and Ismaeli sects). The anti-Soviet Basmachi movement was strong in Tadzhikistan leading Stalin to resettle many from the mountains to sparsely populated plains areas.

TURKMENIA: Borders Afghanistan and Iran along the Kara-Kum Desert. Capital: Ashkhabad. Population: 2.5 million. Largest of the four republics, the size of Colorado and Wyoming combined. Major industries are natural gas fields and oil refining near the Caspian Sea. Cotton, silk, and fruits and vegetables in irrigated zones, and Karakul sheep raising in the deserts as well as canal and horse breeding dominate agriculture. Turkmeni women are the master weavers of world-famous Bukhara carpets.

UZBEKISTAN: Lying north of the other central Asian republics. Capital: Tashkent. Most populous central Asian Republic with 13 million population. About the size of California. A major oil and gas producer, its agriculture raises two-thirds of Soviet cotton, as well as grain and some fruit and vegetables. The Uzbeks, a Turkish-speaking people, comprise more than 60 per cent of the poulation, and like most other Turkish people of the interior, are considered to be Sunni Moslems. CAPTION: Map, Soviet Islam, By Dare Cook-The Washington Post