The Russian Federation is divided into 83 federal subjects (constituent units), 21 of which are republics. The republics represent areas of non-Russian ethnicity. The indigenous ethnic group of a republic that gives it its name is referred to as the "titular nationality". Due to decades (in some cases centuries) of internal migration inside Russia, each nationality is not necessarily a majority of a republic's population.
Republics differ from other federal subjects in that they have the right to establish their own official language and have their own constitution. Other federal subjects, such as krais (territories) and oblasts (provinces), do not have this right. The chief executives of many republics used to have the title of president, but in 2010 the amendment to the federal law has been adopted that reserves such title exclusively for the head of the Russian state. 
The level of actual autonomy granted to such political units varies but is generally quite extensive. The parliamentary assemblies of such republics have often enacted laws which are at odds with the federal constitution. The republics' executives tend to be very powerful. However, this autonomy was lessened considerably under former President of the Russian Federation Vladimir Putin who sought to impose the supremacy of the federal constitution.
The establishment of seven large "federal districts" above the regions and republics of Russia, with presidentially appointed governors overseeing the republics' activities, has strengthened the rule of law, and respect for the constitution in the republics. In addition, Putin strengthened the position of the republics' legislatures while weakening the executives power. The executive heads of republics are now appointed by the President of Russia himself. The President's nomination must be accepted by the republic's parliament.
There are secessionist movements in most republics, but these are generally not very strong. However, there was considerable support for secession among Tatars, Bashkirs, Yakuts, and Chechens after the break-up of Soviet Union, resulting in war in the case of Chechnya. The desire for secession in many republics is, however, greatly complicated by the extent to which other ethnic groups reside in their titular republics (Tatarstan, Bashkortostan, Sakha). (As a result of the First and Second Chechen Wars, very few non-Chechens now reside in Chechnya). Also, the majority of Tatars, unlike other titular ethnic groups, reside outside of Tatarstan.
The Russian SFSR of the former Soviet Union included three types of ethnic constituent units, viz., in the order of decreasing "autonomy" level: Autonomous Soviet Socialist Republics (or simply autonomous republics), autonomous oblasts, and autonomous okrugs.
After the dissolution of the USSR, each "autonomous republic" was succeeded by a republic with a similar name (or, in the case of the Chechen-Ingush ASSR, by two republics: Chechnya and Ingushetia). Several "autonomous oblasts" (Adygea, Altai, Karachay-Cherkessia, Khakassia) have become "republics" as well.
The expression "autonomous republic" is still sometimes used for the republics of Russia. Although they are autonomous and republics, the use of this term is not technically correct, since their official names, as per 1993 Russian Constitution and their own constitutions, are simply "republic", rather than "autonomous republic".
|Republic||Continent||Titular Nationality1||Titular Nationality in Republic's Population (2002)||Titular Nationality: Language Group||Titular Nationality: Main Religion||Ethnic Russians in Republic's Population (2002)||Population (2002)4|
|Adygea (Адыгея, Адыгэ)||Europe||Adyghe||24.2%||Caucasian||Sunni Islam||64.5%||447,000|
|Altai (Алтай)||Asia||Altay||33.5%||Turkic||Burkhanism, Tibetan Buddhism, Shamanism, Orthodox Christianity||57.4%||203,000|
|Bashkortostan (Башкортостан, Башҡортостан)||Europe||Bashkir||29.8%||Turkic||Sunni Islam||36.3%||4,104,000|
|Buryatia (Бурятия, Буряад)||Asia||Buryat||28.1%||Mongolic||Tibetan Buddhism, Shamanism; tiny Russian Orthodox minority known as Onghols, often considered separate ethnic group||67.8%||981,000|
|Chechnya (Чеченская Республика, Нохчийчоь)||Europe||Chechen2||93.5%||Caucasian||Sunni Islam, Sufi Islam||3.7%||1,104,000|
|Chuvashia (Чувашская Республика, Чăваш Республики)||Europe||Chuvash||67.7%||Turkic||Russian Orthodoxy, Islam, shamanism||26.5%||1,314,000|
|Dagestan (Дагестан)||Europe||10 indigenous nationalities3||86.6%||Caucasian, Turkic5||Sunni Islam, Judaism (if Mountain Jews and Jewish Tats are considered)||4.7%||2,577,000|
|Ingushetia (Ингушетия, ГӀалгӀай Мохк)||Europe||Ingush2||77.3%||Caucasian||Sunni Islam, Sufi Islam||1.2%||467,000|
|Kabardino-Balkaria (Кабардино-Балкарская Республика, Къэбэрдей-Балъкъэр, Къабарты-Малкъар)||Europe||Kabard, Balkars||67% (Kabardin 55.3%, Balkars 11.6%)||Caucasian, Turkic||Sunni Islam, Russian Orthodoxy6||25.1%||901,000|
|Kalmykia (Калмыкия, Хальмг Таңһч)||Europe||Kalmyk||53.3%||Mongolic||Tibetan Buddhism||33.6%||292,000|
|Karachay-Cherkessia (Карачаево-Черкесская Республика)||Europe||Karachai, Cherkess||50% (Karachai 38.5%, Cherkess 11.3%)||Turkic, Caucasian||Sunni Islam||33.6%||439,000|
|Karelia (Карелия, Karjala)||Europe||Karelians||9.2%||Finno-Ugric||Russian Orthodoxy||76.6%||716,000|
|Khakassia (Хакасия)||Asia||Khakas||12.0%||Turkic||shamanism, Russian Orthodoxy||80.3%||546,000|
|Komi (Коми)||Europe||Komi people||25.2%||Finno-Ugric||Russian Orthodoxy, shamanism||59.6%||1,019,000|
|Mari El (Марий Эл)||Europe||Mari||42.9%||Finno-Ugric||Russian Orthodoxy, indigenous pagan faith, Marla faith||47.5%||728,000|
|Mordovia (Мордовия)||Europe||Mordvin||31.9%||Finno-Ugric||Russian Orthodoxy||60.8%||889,000|
|North Ossetia-Alania (Северная Осетия-Алания, Цӕгат Ирыстоны Аланийы)||Europe||Ossetian||62.7%||Iranian||Eastern Orthodoxy, Sunni minority||23.2%||710,000|
|Sakha (Yakutia) (Саха (Якутия))||Asia||Yakut||45.5%||Turkic||Russian Orthodoxy, Shamanism||41.2%||949,000|
|Tatarstan (Татарстан, Tatar Cyrillic: Татарстан, Latin: Tatarstan)||Europe||Tatar||52.9%||Turkic||Sunni Islam||39.5%||3,779,000|
|Tuva (Тыва)||Asia||Tuvans||77.0%||Turkic||Tibetan Buddhism, Shamanism, tiny Russian Orthodox minority||20.1%||306,000|
|Udmurtia (Удмуртская Республика, Удмурт Элькун)||Europe||Udmurts||29.3%||Finno-Ugric||Russian Orthodoxy||60.1%||1,570,000|