According to some suggestions, Kars was founded in the 4th century. However, references to the city were found in the Armenian and Byzantine chronicles since the 9th century. By this time, Kars was a major trade and craft center, through which trade routes to different countries were going.
In the beginning, the fortress of Kars had barracks, warehouses with food and ammunition inside its walls, but there were no civilian buildings. However, in the 17th century, there already were 3,000 houses and many shops inside the fortress.
The city-fortress was of great importance in the state and public life of medieval Armenia. It was the center of the area of Vanand of the Ayrarat province.
The city was also a major center of craft and trade. In 928-961, the city was the capital of Armenia, but in 961, Armenian King Ashot III moved the capital to Ani.
In the 10th-11th centuries, Kars remained the capital of the Vanand or Kars Kingdom run by the younger branch of the Armenian royal dynasty, the Bagratids.
In 1065, the Kars Kingdom had been annexed to Byzantium and was later conquered by the Seljuks. Together with a part of Northern Armenia, it was liberated by the Zakaryans in 1206 and entered the Kingdom of Georgia.
In the 16th century, Kars was captured by the Turks, who turned it into a stronghold for spreading their influence in Transcaucasia.
In the 19th century, Russian troops took Kars three times during the Russian-Turkish wars, but the city was returned to Turkey under the terms of the peace treaties the first two times.
Only in 1878, Kars became a part of the Russian Empire and remained within it until its collapse in 1917. By the terms of the Treaty of Brest-Litovsk in 1918, Turkey took control of Kars again.
After the defeat of the Turks in World War I, the city was passed to Armenia, but not for long. In 1921, the Kars Treaty was signed between Turkey and Bolshevik Russia, which forced the Armenians to give away Kars along with Mount Ararat to Turkey.