It is historically descended from the Mitsubishi zaibatsu, a unified company which existed from 1870, founded by Iwasaki Yatarō, to 1947 and was disbanded during the occupation of Japan following World War II. The former constituents of the company continue to share the Mitsubishi brand and trademark. Although the group companies participate in limited business cooperation, most famously through monthly "Friday Conference" executive meetings, they are formally independent and are not under common control. The four main companies in the group are MUFG Bank (the largest bank in Japan), Mitsubishi Corporation (a general trading company), Mitsubishi Electric
and Mitsubishi Heavy Industries (both being diversified manufacturing companies).
Yatarō Iwasaki, the founder of Mitsubishi
The Mitsubishi company was established as a shipping firm by Yatarō Iwasaki (1834–1885) in 1870. In 1873, its name was changed to Mitsubishi Shokai. The name Mitsubishi (三菱) consists of two parts: "mitsu" meaning "three" and "hishi" (which becomes "bishi" under rendaku) meaning "water caltrop" (also called "water chestnut"), and hence "rhombus", which is reflected in the company's logo. It is also translated as "three diamonds".
Mitsubishi was established in 1870, two years after the Meiji Restoration, with shipping as its core business. Its diversification was mostly into related fields. It entered into coal-mining to gain the coal needed for ships, bought a shipbuilding yard from the government to repair the ships it used, founded an iron mill to supply iron to the shipbuilding yard, started a marine insurance business to cater for its shipping business, and so forth. Later, the managerial resources and technological capabilities acquired through the operation of shipbuilding were utilized to expand the business further into the manufacture of aircraft and equipment. The experience of overseas shipping led the firm to enter into a trading business.
In 1881, the company bought into coal mining by acquiring the Takashima Mine, followed by Hashima Island in 1890, using the production to fuel their extensive steamship fleet. They also diversified into shipbuilding, banking, insurance, warehousing, and trade. Later diversification carried the organization into such sectors as paper, steel, glass, electrical equipment, aircraft, oil, and real estate. As Mitsubishi built a broadly based conglomerate, it played a central role in the modernization of Japanese industry.
In February 1921, the Mitsubishi Internal Combustion Engine Manufacturing Company in Nagoya invited British Sopwith Camel designer Herbert Smith, along with several other former Sopwith engineers to assist in creating an aircraft manufacturing division. After moving to Japan, they designed the Mitsubishi 1MT, Mitsubishi B1M, Mitsubishi 1MF, and Mitsubishi 2MR.
The merchant fleet entered into a period of diversification that would eventually result in the creation of three entities:
Mitsubishi Bank (now a part of the Mitsubishi UFJ Financial Group) was founded in 1919. After its mergers with the Bank of Tokyo in 1996, and UFJ Holdings in 2004, this became Japan's largest bank.
Mitsubishi Corporation, founded in 1950, Japan's largest general trading company
Mitsubishi Heavy Industries, which includes these industrial companies:
Mitsubishi Motors, the sixth-largest Japan-based car manufacturer.
Mitsubishi Atomic Industry, a nuclear power company.
Mitsubishi Chemical, the largest Japan-based chemicals company
Mitsubishi Hitachi Power Systems, a power generation division
Nikon Corporation, specializing in optics and imaging.
The firm's prime real estate holdings in the Marunouchi district of Tokyo, acquired in 1890, were spun off in 1937 to form Mitsubishi Estate, now one of the largest real estate development companies in Japan.