sentences:  In 1920, Turkish nationalist forces invaded the fledgling Armenian republic from the east.Turkish forces under the command of Kazım Karabekir captured Armenian territories that Russia had annexed in the aftermath of the 1877–1878 Russo-Turkish War and occupied the old city of Alexandropol (present-day Gyumri).The violent conflict finally concluded with the Treaty of Alexandropol on 2 December 1920.