Sumitomo’s long-managed Besshi Copper Mine (opened in 1691) remained central as Japan industrialized after 1868. Copper output supported exports and supplied growing domestic industry, helping Sumitomo finance diversification into new lines of business. Resource-based earnings like this were one path into zaibatsu-scale growth.
The Meiji Restoration replaced the shogunate and launched major state-led modernization efforts. The new government encouraged industrial development and overseas trade, creating openings for large private business groups. These conditions helped older merchant houses and new entrepreneurs expand into modern conglomerates later called zaibatsu.
In March 1870, Iwasaki Yatarō became president of the Tsukumo Trading Company, a shipping business linked to the former Tosa domain. This step provided ships and commercial networks that Mitsubishi later used as its base. It also showed how early Meiji-era political connections could support rapid private expansion.
In March 1873, Iwasaki’s company adopted the name “Mitsubishi,” meaning “three diamonds,” linked to family and clan crests. A recognizable name and emblem helped the firm build a unified identity as it expanded. The shipping firm would later diversify into mining, shipbuilding, and finance—typical zaibatsu patterns.
On July 1, 1876, Mitsui Bank was founded as a private company, often described as Japan’s first private bank. Having a bank allowed the Mitsui group to mobilize capital and finance other businesses. Banking became a key tool for zaibatsu growth and influence.
In 1876, Mitsui took over a predecessor trading house and founded Mitsui Bussan (later Mitsui & Co.), with Takashi Masuda as the leading manager. A general trading company could coordinate exports, imports, shipping, and overseas offices. This strengthened Mitsui’s ability to expand beyond domestic retail and finance into global commerce and industrial supply chains.
In 1880, Yasuda Bank was formed, becoming the core of the Yasuda financial group. Along with Mitsui, Mitsubishi, and Sumitomo, Yasuda later came to be recognized as one of the “Big Four” zaibatsu. This highlights that zaibatsu power often rested on finance as much as manufacturing.
In 1884, Iwasaki leased the government-owned Nagasaki Shipyard and began shipbuilding on a full scale. Controlling shipbuilding reduced reliance on outside suppliers for the shipping business and pushed Mitsubishi into heavy industry. This move became a foundation for later industrial expansion under the Mitsubishi group.
As the Meiji state sold off major industrial assets, Mitsui took over the Miike Coal Mine in 1889. Coal was critical for steamships, railways, and heavy industry, so control of a major mine supported broader industrial growth. The purchase also shows how government privatization helped concentrate key resources in a few large groups.
Sumitomo Bank was founded in November 1895 in Osaka, becoming a central institution within the Sumitomo group. A dedicated bank helped coordinate financing for mining, trading, and manufacturing activities. This banking-centered structure was a hallmark of zaibatsu organization.
In 1909, Mitsui Gomei Kaisha was established as a holding company dominated by Mitsui family partners. A holding company could coordinate strategy, ownership, and capital allocation across many legally separate firms. This corporate structure helped make large-scale, multi-industry control more systematic.
In the 1920s and early 1930s, the big zaibatsu were widely seen as dominant forces in Japan’s economy. They combined family-linked ownership with banks, trading companies, and industrial subsidiaries across many sectors. Their scale allowed them to shape investment and production during a period of economic volatility and rising state priorities.
Mitsubishi expanded into aircraft production as military demand grew, with Mitsubishi Aircraft Company recorded as founded in 1928. Moving into aircraft linked the group more tightly to advanced manufacturing and defense procurement. This was part of a broader trend in which large conglomerates concentrated strategic industries within their corporate networks.
In 1934, Mitsubishi Heavy Industries was launched, consolidating major heavy industrial activities under one large company. The firm manufactured ships, heavy machinery, and aircraft, showing how zaibatsu groups combined multiple industrial lines into coordinated systems. By the mid-1930s, this kind of consolidation marked the mature stage of prewar conglomerate formation.
Rise of the zaibatsu: Mitsubishi, Mitsui, Sumitomo and conglomerate formation (1870s-1930s)