Tbilisi, formerly Tiflis, capital of the republic of Georgia, on the Mtkvari (Kura) River at its dissection of the Trialeti (Trialetsky) and Kartli (Kartliysky, or Kartalinian) ranges. Founded in 458 (in some sources, 455), when the capital of the Georgian kingdom was transferred there from Mtskheta, the city had a strategic position, controlling the route between western and eastern Transcaucasia. It was often captured and sacked and knew many masters: the Persians in the 6th century, the Byzantine Empire and the Arabs in the 7th. In 1122 David IV (the Builder) of Georgia captured Tbilisi and restored it as a capital, but in 1234 it fell to the Mongols, and in 1386 it was sacked by Timur. The Turks captured the city on several occasions, and in 1795 it was burned to the ground by the Persians. In 1801 Tbilisi was captured by the Russians, who improved its communications by building the Georgian Military Highway across the Greater Caucasus from Vladikavkaz to Tbilisi. In 1872 it was linked by rail to Poti on the Black Sea and in 1883 to Baku on the Caspian Sea. In 1921 it was made capital of the Georgian republic.

Modern Tbilisi is an attractive city: the Mtkvari, bordered on the right bank by a boulevard, lies partly in a steep gorge and is made broader by the Ortachalskaya hydroelectric plant in the city. Beside the river, the old town, with narrow, winding streets, is dominated by the ruins of the old fortress and the huge, symbolic figure of Georgia on a ridge above it. In the old town are the Sioni Cathedral, dating from the 5th century and often reconstructed, the Metekhi Palace of the Georgian kings, and the 6th-century Anchiskhati Church. Newer parts of the city lie beneath Mount Mtatsminda, accessible by a funicular rail line. North of the city is a large reservoir fed by irrigation canals.

Tbilisi is a major cultural and educational centre, with a university, several other institutions of higher education, and more than 100 research establishments. The city is a principal industrial centre of the region. Its engineering services are important in the production of electric locomotives, machine tools, agricultural machinery, and electrical equipment and in the repair of locomotives and rolling stock. Other industries make textiles; leather goods and footwear; furniture; beer, wine, and spirits; and a range of foodstuffs. In 1966 an underground railway was opened in Tbilisi. Pop. (2014) 1,108,717; (2017 est.) 1,114,600.