Tokyo formally a Tokyo Metropolis, it is one of the 47 prefectures of Japan. Tokyo is measured to be one of the world's most significant and powerful global cities. It has aided as the Japanese capital since 1869 its urban area covering the Emperor of Japan and the Japanese government. Tokyo procedures part of the Kant? region on the southeastern side of Japan's main island, Honshu, and contains the Izu Islands and Ogasawara Islands. Tokyo was previously named Edo when Sh?gun Tokugawa Ieyasu made the city his headquarters in 1603. It developed the capital after Emperor Meiji stimulated his seat to the city from Kyoto in 1868. The Tokyo Metropolis formed in 1943 from the union of the former Tokyo Prefecture and the city of Tokyo. Tokyo is frequently mentioned to as a city but is formally known and governed as a "metropolitan prefecture", which varies from and combines elements of a city.