By the Treaty of San Stefano, ending the Russo-Turkish War (1877–1878), Russia gained considerable land in what is now eastern Turkey (termed Western Armenia), extending the Ottoman-Russian frontier south-westwards.[1][7][8] Russia's gains of Batumi, Kars and Ardahan were confirmed by the Treaty of Berlin (1878), though it was compelled to hand back part of the area around Bayazid (modern Doğubayazıt) and the Eleşkirt valley.[4][4][9]