The Vilayet of Van (Vilâyet-i Van; Vani vilayet) was a first-level administrative division (vilayet) of the Ottoman Empire. At the beginning of the 20th century, it reportedly had a population of about 400,000 and an area of . Van Vilayet was one of the six Armenian vilayets and held, prior to the Armenian genocide during World War I, possessed a majority Armenian population, as well as Kurdish, Assyrian and Azeri minorities. In 1875, the eyalet of Erzurum was divided in six vilayets: Erzurum, Van, Hakkari, Bitlis, Hozat (Dersim) and Kars-Çildir. In 1888, by an imperial order Hakkari was joined to the vilayet of Van, and Hozat to Mamuret ul-Aziz. As the border province of the north-eastern frontier, towards both the Russian Empire and Qajar Iran, it contained a number of garrisons. It was divided into the Sanjak of Van and the Sanjak of Hakkari and covered the present-day provinces of Van, Hakkari and parts of Şırnak, Muş and Bingöl ones. During the Caucasus campaign of World War I, the Russians planned to invade the province after the breakdown of the Ottoman Army's offensive into Russia. The invasion threat led the Committee of Union and Progress to begin the Armenian genocide out of fear that Armenians in Van would support the Russian Caucasus Army. The deportation of Armenians from Constantinople to the Van uprising by Armenian fedayi. At the beginning of the 20th century, Van Vilayet reportedly had an area of , while the preliminary results of the first Ottoman census of 1885 (published in 1908) gave the population as 376,297. The accuracy of the population figures ranges from "approximate" to "merely conjectural" depending on the region from which they were gathered. Based on the official 1914 Ottoman Census, the population of Van province consisted of 179,422 Muslims and 67,797 Armenians. The Ottoman Census figures include only male citizens, excluding women and children. According to Armenian Patriarch of Constantinople, the corrected estimates for Van province (including women and children) was; 313,000 Muslims, 130,000 Armenians, and 65,000 others, including Syriac Christians and Nestorians.