sentences:  Tbilisi became a veritable cultural center for Eastern Armenians ("arevelahayer", commonly called Russian-Armenians "rusahayer") just like Istanbul in Turkey became cultural center for the Western Armenians ("arevmedahayer", commonly called Turkish-Armenians "turkahayer" at the time).As a result of the struggles of the Russian Empire with the Ottomans and its conquest of the Caucasus over the Qajar Iran, the Russian authorities found themselves able to settle Christian Armenian and Greek refugees in the area after 1828, following the ratified Treaty of Turkmenchay with Qajar Iran of 1828, and the Treaty of Adrianople with Ottoman Turkey of 1829.Armenians left rich architectural imprint in Georgia, and Tbilisi has many architectural buildings constructed by Armenian architects of the last centuries.