In anticipation of April 2015, the Armenian State Centennial Commemoration Commission, established by Presidential decree on April 23, 2011, adopted a floral symbol, a purple forget-me-not, to promote awareness of the upcoming centenary of the Ottoman Turkish pogrom against Anatolian Armenians. Bulgaria's contemporary Armenian diaspora comprises a more established community of Anatolian or western Armenians, largely descendants of refugees from Istanbul and Turkish Thrace displaced between 1894 and 1922, and Caucasus or eastern Armenians who have immigrated from the post-Soviet Republic since 1991. Eastern and western Armenians speak almost mutually unintelligible dialects, and the community remains fairly segregated. After the Easter morning liturgy, about 300 community members made pilgrimage on foot from the present Armenian church and cultural center to "Erevan," located a half-mile away. The Great Catastrophe has been commemorated annually in Sofia at a small park called "Erevan," a gift to the Armenian community from city mayor Boiko Borisov.