In 963, shortly after the Bagratid capital was transferred to Ani, Kars became the capital of a separate independent kingdom, again called Vanand. The extent of its actual independence from the Kingdom of Ani is uncertain: it was always held by relatives of the rulers of Ani and, after Ani's capture by the Byzantine Empire in 1045, the Bagratid title "King of Kings" held by the ruler of Ani was transferred to the ruler of Kars.
In 1064, just after the capture of Ani by the Seljuk Turks, the Armenian king of Kars, Gagik II, paid homage to the victorious Turks to avoid them laying siege to his city. In 1065 Gagik ceded control of Kars to the Byzantine Empire, but soon afterwards they lost it to the Seljuk Turks. In 1206/1207 the city was captured by the Georgians and given to the same Zakarid family who ruled Ani. They retained control of Kars until the late 1230s, after which it was ruled by a series of petty Turkish emirs.
In 1387 the city surrendered to Timur (Tamerlane) and its fortifications were slighted. More petty Turkish emirs followed until 1534, when the Ottoman army captured the city. The fortifications of the city were rebuilt by the Ottoman Sultan Murad III and were strong enough to withstand a siege by Nadir Shah of Persia, in 1731. It became the head of a sanjak in the Turkish vilayet of Erzurum.
In 1807 Kars successfully resisted an attack by the Russian Empire, but after another siege in 1828 it was surrendered on June 23, 1828 to the Russian general Count Ivan Paskevich, 11,000 men becoming prisoners of war. Although it was afterwards returned to Turkey, the new border between Turkey and Russia lay much closer to Kars. During the Crimean War a Turkish garrison led by British officers including General William Fenwick Williams kept the Russians at bay during a protracted siege; but after the garrison had been devastated by cholera and food had utterly failed, the town was surrendered to General Mouravieff in November 1855.
The fortress was again stormed by the Russians in the Battle of Kars during the Russo-Turkish War, 1877-78 under generals Loris-Melikov and Ivan Lazarev and on its conclusion was transferred to Russia by the Treaty of San Stefano. Kars became the capital of Kars Oblast (province), comprising the districts of Kars, Ardahan, Kağızman, and Oltu.
From 1878-1881 more than 82,000 Muslims from formerly Turkish-controlled territory migrated to the Ottoman Empire, of them more than 11,000 left from the city of Kars. At the same time, many Armenians and Greeks migrated to the region from the Ottoman Empire and other regions of Transcaucasia. According to the Russian census data, by 1892 Russians made 7%, Greeks 13.5%, Kurds 15%, Armenians 21,5%, Turks 24%, Karapapakhs 14%, and Turkmen 5% of the population of Kars oblast.
Russia ceded Kars, Ardahan and Batum to the Ottoman Empire under the Treaty of Brest-Litovsk on March 3, 1918. However, by then Kars was under the effective control of Armenian and non-Bolshevik Russian forces. The Ottoman empire captured Kars on April 25, 1918, but under the Armistice of Mudros (October 1918) was required to withdraw to its 1914 frontier. The Ottomans refused to relinquish Kars; its military governor instead constituting a provisional government, the South West Caucasian Government, led by Fahrettin Pirioglu, that claimed Turkish sovereignty over Kars and the Turkish-speaking and Islamic neighbouring regions as far as Batumi and Alexandropol (Gyumri). Much of the region was occupied by the Democratic Republic of Armenia (DRA) in January 1919 but the pro-Turkish government remained in the city until the arrival of the British troops, who dissolved it on April 19, 1919, arresting its leaders and sending them to Malta. In May 1919 Kars came under the full administration of the Armenian Republic and became the capital of its Vanand province.
Skirmishes between Turkish revolutionaries and Armenian border troops in Oltu led to an invasion of the Armenian Republic by four Turkish battalions under the command of General Kazım Karabekir, triggering the Turkish-Armenian War. The war led to the capture of Kars by Turkish forces on October 30, 1920. The terms of the Treaty of Alexandropol, signed by the representatives of Armenia and Turkey on December 2, 1920, forced the DRA to cede more than 50% of its pre-war territory and to give up all the territories granted to it at the Treaty of Sèvres. After the Bolshevik invasion of Armenia, the Alexandropol treaty was superseded by the Treaty of Kars (October 23, 1921), signed between Turkey and the Soviet Union. The treaty allowed for Soviet annexation of Adjara in exchange for Turkish control of the regions of Kars, Iğdır, and Ardahan. The treaty established peaceful relations between the two nations, but as early as 1939, some British diplomats noted indications that the Soviet Union was not satisfied with the established border. On more than one occasion, the Soviets attempted to renegotiate with Turkey to at least allow the Armenians access to the ancient ruins of Ani. However, Ankara refused these attempts.
After World War II, the Soviet Union attempted to annul the Kars treaty and regain its lost territory. On June 7, 1945, Soviet Foreign Minister Vyacheslav Molotov told the Turkish ambassador in Moscow that the regions should be returned to the Soviet Union, in the name of both the Georgian and Armenian republics. Turkey found itself in a difficult position: it wanted good relations with the Soviet Union but at the same time they refused to give up the territories. Turkey itself was in no condition to fight a war with the Soviet Union which had emerged as a superpower after the second world war. By the autumn of 1945, Soviet troops in the Caucasus were already assembling for a possible invasion of Turkey. However opposition stemmed from British leader Winston Churchill who objected to these territorial claims as additional areas of where the Soviet government could exert its influence while President Harry S. Truman of the United States felt that matter shouldn't concern other parties. The Cold War was just beginning.
Since the Nagorno-Karabakh War, the borders between Armenia and Turkey have been closed. Kars Mayor Naif Alibeyoğlu, believes that the border should be opened again and that there should be no nationalist sentiment against the Armenians.
Kars Castle (Kars Kalesi), also known as the citadel, sits at the top a rocky hill overlooking Kars. Its walls date back to the Bagratid Armenian period (there is surviving masonry on the north side of the castle) but it probably took on its present form during the 13th century when Kars was ruled by the Zakarid dynasty. The walls bear crosses in several places, including a khachkar with a building inscription in Armenian on the easternmost tower, so the much repeated statement that Kars kastle was built by Ottoman Sultan Murad III during the war with Persia, at the close of the 16th century, is inaccurate. However, Murad probably did reconstruct much of the city walls (they are similar to those that the Ottoman army constructed at Ardahan).
The "Taşköprü" (Stone Bridge) is a bridge over the Kars river, built in 1725. Close to the bridge are three old bath-houses.
Kars is served by a station on the Turkish Railways (TCDD). The line continues into Armenia. However the actual border crossing has been closed since 1993. There is a proposal to construct a branch that will connect Kars with Akhalkalaki in Georgia, and thence to Tbilisi, and Baku in Azerbaijan.