6 September - day of Bulgarian unification. The Unification of Bulgaria (Bulgarian: Съединение на България, Saedinenie na Balgariya) was the act of unification of the Principality of Bulgaria and the province of Eastern Rumelia in the autumn of 1885. It was co-ordinated by the Bulgarian Secret Central Revolutionary Committee (BSCRC). Both had been parts of the Ottoman Empire, but the Principality had functioned de facto independently whilst the Rumelian province was autonomous and had an Ottoman presence. The Unification was accomplished after revolts in Eastern Rumelian towns, followed by a coup on 18 September [O.S. 6 September] 1885 supported by the Bulgarian Knyaz Alexander I. The BSCRC, formed by Zahari Stoyanov, began actively popularizing the idea of unification by means of the press and public demonstrations in the spring of 1885.