It is said that "Uogashi" or a riverside fish market dates back to the 16th century, the beginning of the Edo period. In 1923 some 20 private markets in Tokyo were destroyed almost completely by the Great Kanto Earthquake. After the earthquake, Tokyo City as it then was undertook to construct a central wholesale market on the bases of the Central Wholesale Market Law which had been promulgated in the same year. As a result, the three markets of Tsukiji, Kanda and Koto were founded and the growing population then led to a succession of new markets.