Why it's the capital
King Vakhtang I of Iberia founded the city in the 5th century. His successor, King Dachi, who ruled from 522 to 534, moved the capital of Iberia here from Mtskheta and began building the city's fortress wall.
Capital of GeorgiaTbilisi stretches along both banks of the Kura River, called the Mtkvari locally, in eastern Georgia in the South Caucasus, between about 380 and 770 m above sea level.
King Vakhtang I of Iberia founded the city in the 5th century. His successor, King Dachi, who ruled from 522 to 534, moved the capital of Iberia here from Mtskheta and began building the city's fortress wall.
Georgia lies between the Black Sea and the Caspian Sea; aim at its eastern half, on the Kura River, almost straight north of Yerevan.
Sources: Wikipedia: Tbilisi