The Tophane Agreement was a treaty between the Principality of Bulgaria and the Ottoman Empire signed on 5 April [O.S. 24 March] 1886 during an ambassadorial conference in Istanbul. The agreement was named after the Istanbul neighborhood Tophane, located in Beyoğlu district, where the treaty was signed.
Signed by the Ottoman Grand Vizier Mehmed Kamil Pasha and the Bulgarian foreign minister Iliya Tsanov, as well the ambassadors of the Great Powers, the agreement recognized the Prince of Bulgaria (Alexander Batenberg at the time) as Governor-General of the autonomous Ottoman Province Eastern Rumelia. In this way, the de facto Unification of Bulgaria which had taken place on 18 September [O.S. 6 September] 1885, was de jure recognized.
As compensation, the Ottoman Empire received the area around Kardzhali, as well as the Republic of Tamrash, for a total area of 1,640 km². With this treaty, the territory of the unified Bulgaria became 94,345 km². Bulgaria later regained the lands lost in this treaty following victory in the First Balkan War (1912–13).
- Hertslet, Edward (1891), "Act agreed between the Plenipotentiaries of Great Britain, Austria-Hungary, France, Germany, Italy, Russia, and Turkey, for modifying Articles XV and XVII of the Treaty of Berlin; Governor-Generalship of Eastern Rumelia to be entrusted to the Prince of Bulgaria, and Musulman Villages of Kirdjali and those of Rhodope District to be placed under administration of the Porte, Constantinople, 5th April 1886. (Translation)", The Map of Europe by Treaty; which have taken place since the general peace of 1814. With numerous maps and notes, IV (1875-1891) (First ed.), London: Her Majesty's Stationery Office, pp. 3152–3157, retrieved 2013-01-04
- Raymond Detrez: Historical Dictionary of Bulgaria, Scarecrow Press, London 1997, ISBN 0-8108-3177-5, P. 437
- Magarditsch A. Hatschikjan: Tradition und Neuorientierung in der bulgarischen Außenpolitik 1944 - 1948. Die "nationale Außenpolitik" der Bulgarischen Arbeiterpartei (Kommunisten). Verlag Oldenburg, München 1988, ISBN 3-486-55001-2, P. 20