Known as Edo until 1868, Tokyo is a coastal city with an intricate history. In 1457, Edo Castle was constructed and in 1603 it became the seat of the Tokugawa Shogunate. Under the Tokugawas, the city was constructed in order to profit from the natural waterways that serve as transportation canals. By the early 1700's, the population of Tokyo was already estimated at 1.2 million, while the population of London and Paris was 650,000 and 500,000 respectively. In 1868, with the overthrow of the Tokugawas and the beginning of the Meiji era, Edo became capital of Japan under a new name, Tokyo, which means "Capital of the East".
At the beginning of the Second World War, after intensive modernization, Tokyo had a population of 7.4 million, despite the Great Earthquake of 1923. In 1950 the population was 6.9 million and doubled to 16.5 million in 1970. In 1995, the estimated population of the urban agglomeration was 26.8 million.
Tokyo has a concentration of light manufacturing but also produces goods which require a sizable workforce, such as electrical products, cameras and automobiles. Most establishments, however, are small shops with fewer than 30 workers.
Tokyo serves as a wholesaling and distribution centre for surrounding areas, and is also the chief financial centre of Japan. Tokyo houses many domestic and international corporate headquarters.
After the Second World War, Tokyo experienced a large housing demand which it could not satisfy. The 1970's and 1980's witnessed a surge in construction of multistory condominiums intended for sale. However, the prices soared making them inaccessible and unable to meet the needs of the city.
Though Tokyo, like other major cities, suffers from traffic congestion, the main congestion is on the public system during peak hours. The major method of transportation in Tokyo is the dense network of electric railways, subways, and bus lines, which keeps pollution from cars relatively low.
Water is supplied by aqueduct systems to the metropolitan area. Local waterworks and private industrial and residential systems supplement the municipal water supply. The main sources of water are the Tama and Tone-Edo rivers and three reservoirs. However, in order to meet increasing demand, additional dams have been built on nearby rivers, which is causing the eastern lowlands area to subside.
The rapid growth of the metropolitan area stressed the sewage system which in turn resulted in the decrease of water quality. However, since the 1960's, sewage systems have improved and refuse is now incinerated, recycled or reused.
Periodically, there have been proposals to relocate the nation's capital away from Tokyo in an effort to decentralize. However, to date none have come close to implementation.