The Vilayets of the Ottoman Empire were the first-order administrative division, or provinces, of the later empire, introduced with the promulgation of the Vilayet Law  of 21 January 1867. The reform was part of the ongoing administrative reforms that were being enacted throughout the empire, and enshrined in the Imperial Edict of 1856. The reform was at first implemented experimentally in the Danube Vilayet, specially formed in 1864 and headed by the leading reformist Midhat Pasha. The reform was gradually implemented, and not until 1884 was it applied to the entirety of the Empire's provinces.