Mitsubishi had been 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. Similarly, the experience of overseas shipping led the firm to enter into a trading business.
Mitsubishi's automotive origins date back as far as 1917, when the Mitsubishi Shipbuilding Co., Ltd. introduced the Model A, Japan's first series-production automobile.An entirely hand-built seven-seater sedan based on the Fiat Tipo 3, it proved expensive compared to its American and European mass-produced rivals, and was discontinued in 1921 after only 22 had been built.
Source:Wikipedia