Tokyo is also one of Japan's 47 prefectures, but is called a metropolis.The metropolis of Tokyo consists of 23 city wards, 26 cities, 5 towns and 8 villages, including the Izu and Ogasawara Islands.

The 23 city wards are the center of Tokyo and
make up about one third of the metropolis' area.

Prior to 1868, Tokyo was known as Edo. A small castle town in the 16th century, Edo became Japan's political center in 1603
when Tokugawa Ieyasu established his feudal government there. Decades later, Edo had grown into one of the world's most populous cities.