The Ottoman rule of Armenia or Ottoman Armenia, beginning with the rule of Selim II (1524 – 1574) becomes the integral part of the Ottoman Empire. However, the initial accession begins with Mehmed II, who also offered the Ottoman support to initiate Armenian Patriarch in Constantinople. This rule continued 300 years till the following the Russo–Turkish War (1828–1829), when the Eastern Armenia of this territory was ceded to the Russian Empire. The remaining Ottoman Armenia, composed of 6 vilayets (Erzurum, Van, Bitlis, Diyarbekir, Kharput, and Sivas[1]), till World War I, under Ottoman rule was also referred to as Western Armenia.