From the second half of the 18th century onwards , the Ottoman Empire began to decline . The Tanzimat reforms of the 19th century , which had been instituted by Mahmud II , were aimed to modernise the Ottoman state in line with the progress that had been made in Western Europe . The efforts of Midhat Pasha during the late Tanzimat era led the Ottoman constitutional movement of 1876 , which introduced the First Constitutional Era , but these efforts proved to be inadequate in most fields , and failed to stop the dissolution of the empire . As the empire gradually shrank in size , military power and wealth , especially after the Ottoman economic crisis and default in 1875 which led to uprisings in the Balkan provinces that culminated into the Russo-Turkish War of 1877 – 78 , many Balkan Muslims migrated to the Empire 's heartland in Anatolia , along with the Circassians fleeing the Russian conquest of the Caucasus . The decline of the Ottoman Empire led to a rise in nationalist sentiment among its various subject peoples , leading to increased ethnic tensions which occasionally burst into violence , such as the Hamidian massacres of Armenians
Hamidian massacres
Hamidian massacres
Turkey