Dagestan is a republic of Russia situated in the North Caucasus, bordering the Caspian Sea, with Makhachkala as its capital and largest city. It is one of the most ethnically and linguistically diverse regions in the world, home to over 3.1 million people from more than 30 ethnic groups and 14 official languages, with Russian serving as the common lingua franca. The name translates from Turkic and Persian as "land of the mountains," fitting its rugged terrain dominated by the Greater Caucasus, including its highest peak, Bazardüzü (4,446 m), on the border with Azerbaijan. Historically, the area was known as Dagestan Oblast (1860–1920) before becoming the Dagestan Autonomous Soviet Socialist Republic in 1921, which established its current borders. Internationally, Dagestan is renowned for its strong combat sambo culture, which has produced many successful mixed martial arts fighters.