In the 18th and 19th centuries, Armenian merchants, including famous jewelers and oil industrialists invested heavily in business in Georgia and helped build trading houses, cultural centers, schools and churches. The number of Armenians increased progressively such that by the early 19th century, the Armenians far outnumbered Georgians in the capital city of Tbilisi. 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).