Ignatyev's success was supposed to prove his capacity for dealing with "Orientals" and paved his way to the post of ambassador at Constantinople (Istanbul), which he occupied from 1864 to 1877. Here his chief aim was to liberate the Christian nationalities in general and the Bulgarians in particular from Ottoman domination and bring them under the influence of Russia (See also Bulgarian Exarchate and Constantinople Conference). His restless activity in this field, mostly of a semiofficial and secret character, culminated in the Russo-Turkish War of 1877-1878, at the close of which he negotiated with the Ottoman plenipotentiaries the Treaty of San Stefano.