KARS, Turkey — The history of this city, about 30 miles from the border with Armenia, may best be told through its former Armenian cathedral, the Church of the Holy Apostles, poised at the base of an imposing fortress.

Built in the 10th century by an Armenian king, it was turned into a mosque three times and once into a Russian Orthodox church. It was briefly resurrected as an Armenian church in 1919 before the modern secular Turkish state expropriated it in 1921, eventually turning it into a petroleum depot, then into a museum, then again into a mosque.

Now, it is mostly closed: Many Muslims go instead to a holier shrine next door. According to Armenian news reports, it might be converted into either a cultural center or even a church, but it is unclear who would come, given that virtually no Armenian Christians are left in Kars.

The city has experienced even more violent turnover than its cathedral. The Ottomans and the Russians were here — but also the Byzantines, the Seljuk Turks, the Georgians, the Persians and the Mongols. Populations were imported, expelled and massacred.