Tokyo. Tokyo, officially Tokyo Metropolis, is the capital and most populous prefecture of Japan. Located at the head of Tokyo Bay, the prefecture forms part of the Kanto region on the central Pacific coast of Japan's main island, Honshu. Tokyo is the political and economic center of the country, as well as the seat of the Emperor of Japan and the national government. In 2019, the prefecture had an estimated population of 13,929,280. The Greater Tokyo Area is the most populous metropolitan area in the world, with more than 37.4 million residents as of 2018. Originally a fishing village named Edo, the city became a prominent political center in 1603, when it became the seat of the Tokugawa shogunate. By the mid-18th century, Edo was one of the most populous cities in the world, with a population numbering more than one million. Following the end of the shogunate in 1868, the imperial capital in Kyoto was moved to the city, which was renamed Tokyo. Tokyo was devastated by the 1923 Great Kanto earthquake, and again by Allied bombing raids during World War II. Beginning in the 1950s, the city underwent rapid reconstruction and expansion, going on to lead Japan's post-war economic recovery. Since 1943, the Tokyo Metropolitan Government has administered the prefecture's 23 special wards, various bed towns in the western area, and two outlying island chains. Tokyo is the largest urban economy in the world by gross domestic product, and is categorized as an Alpha+ city by the Globalization and World Cities Research Network. Part of an industrial region that includes the cities of Yokohama, Kawasaki, and Chiba, Tokyo is Japan's leading center of business and finance. In 2019, it hosted 36 of the Fortune Global 500 companies. In 2020, it ranked third on the Global Financial Centres Index, behind New York City and London. The city has hosted multiple international events, including the 1964 Summer Olympics and three G7 Summits; it was also set to host the 2020 Summer Olympics, which were postponed due to the COVID-19 pandemic. Tokyo is an international center of research and development and is represented by several major universities, notably the University of Tokyo. Tokyo Station is the central hub for Japan's Shinkansen bullet train system, and the city is served by an extensive network of rail and subways. Notable districts of Tokyo include Chiyoda, Shinjuku, and Shibuya. The name, which can be translated as estuary, is a reference to the original settlement's location at the meeting of the Sumida River and Tokyo Bay. During the Meiji Restoration in 1868, the name of the city was changed to Tokyo when it became the new imperial capital, in line with the East Asian tradition of including the word capital in the name of the capital city. During the early Meiji period, the city was sometimes called Tokei, an alternative pronunciation for the same characters representing Tokyo, making it a kanji homograph. Some surviving official English documents use the spelling Tokei; however, this pronunciation is now obsolete. Main articles: History of Tokyo and Timeline of Tokyo Tokyo was originally a small fishing village named Edo, in what was formerly part of the old Musashi Province. Edo was first fortified by the Edo clan, in the late twelfth century. In 1457, Ōta Dokan built Edo Castle. In 1590, Tokugawa Ieyasu was transferred from Mikawa Province to Kanto region. When he became shogun in 1603, Edo became the center of his ruling. During the subsequent Edo period, Edo grew into one of the largest cities in the world with a population topping one million by the 18th century. But Edo was Tokugawa's home and was not capital of Japan. The Emperor himself lived in Kyoto from 794 to 1868 as capital of Japan. During the Edo era, the city enjoyed a prolonged period of peace known as the Pax Tokugawa, and in the presence of such peace, Edo adopted a stringent policy of seclusion, which helped to perpetuate the lack of any serious military threat to the city.