The daimy? (, Japanese pronunciation: [daim?o:] ) were powerful Japanese feudal lords who--until their decline in the early Meiji period--ruled most of Japan from their vast, hereditary land holdings. Subordinate to the sh?gun, and nominally to the Emperor and the kuge, daimy? were powerful feudal rulers from the 10th century to the middle 19th century in Japan. In the term, dai (?) means "large", and my? stands for my?den (), meaning private land.
From the Shugo of the Muromachi period through the Sengoku to the daimy? of the Edo period, the rank had a long and varied history. The backgrounds of daimy? also varied considerably; while some daimy? clans, notably the M?ri, Shimazu and Hosokawa, were cadet branches of the Imperial family or were descended from the kuge, other daimy? were promoted from the ranks of the samurai, notably during the Edo period.
Daimy? often hired samurai to guard their land and they paid the samurai in land or food as relatively few could afford to pay samurai in money. The daimy? era ended soon after the Meiji Restoration with the adoption of the prefecture system in 1871.
The shugo daimy? (?) were the first group of men to hold the title daimy?. They arose from among the shugo during the Muromachi period. The shugo-daimy? held not only military and police powers, but also economic power within a province. They accumulated these powers throughout the first decades of the Muromachi period.
The Ashikaga shogunate required the shugo-daimy? to reside in Kyoto, so they appointed relatives or retainers, called shugodai, to represent them in their home provinces. Eventually some of these in turn came to reside in Kyoto, appointing deputies in the provinces.
The ?nin War was a major uprising in which shugo-daimy? fought each other. During this and other wars of the time, kuni ikki, or provincial uprisings, took place as locally powerful warriors sought independence from the shugo-daimy?. The deputies of the shugo-daimy?, living in the provinces, seized the opportunity to strengthen their position. At the end of the fifteenth century, those shugo-daimy? who succeeded remained in power. Those who had failed to exert control over their deputies fell from power and were replaced by a new class, the sengoku-daimy?, who arose from the ranks of the shugodai and ji-samurai.
Among the sengoku daimy? (?) were many who had been shugo-daimy?, such as the Satake, Imagawa, Takeda, Toki, Rokkaku, ?uchi, and Shimazu. New to the ranks of the daimy? were the Asakura, Amago, Nagao, Miyoshi, Ch?sokabe, Jimb?, Hatano, Oda, and Matsunaga. These came from the ranks of the shugodai and their deputies. Additional sengoku-daimy? such as the M?ri, Tamura, and Ry?z?ji arose from the ji-samurai. The lower officials of the shogunate and r?nin (Late H?j?, Sait?), provincial officials (Kitabatake), and kuge (Tosa Ichij?) also gave rise to sengoku-daimy?.
The Battle of Sekigahara in the year 1600 marked the beginning of the Edo period. Sh?gun Tokugawa Ieyasu then reorganized roughly 200 daimy? and their territories into han, which were assessed by rice production. Those heading han assessed at 10,000 koku (50,000 bushels) or more were considered daimy?. Ieyasu also categorized the daimy? according to their relation to the ruling Tokugawa family: the shinpan were related to the Tokugawa; the fudai had been vassals of the Tokugawa or allies in battle; and the tozama had not allied with the Tokugawa before the battle (did not necessarily fight against the Tokugawa).
The shinpan were collaterals of Ieyasu, such as the Matsudaira, or descendants of Ieyasu other than in the main line of succession. Several shinpan, including the Tokugawa of Owari (Nagoya), Kii (Wakayama), and Mito, as well as the Matsudaira of Fukui and Aizu, held large han.
A few fudai daimy?, such as the Ii of Hikone, held large han, but many were small. The shogunate placed many fudai at strategic locations to guard the trade routes and the approaches to Edo. Also, many fudai daimy? took positions in the Edo shogunate, some rising to the position of r?j?. The fact that fudai daimy? could hold government positions while tozama in general, could not was a main difference between the two.
Tozama daimy? held mostly large fiefs far away from the capital, with e.g. the Kaga han of Ishikawa Prefecture, headed by the Maeda clan, assessed at 1,000,000 koku. Other famous tozama clans included the Mori of Ch?sh?, the Shimazu of Satsuma, the Date of Sendai, the Uesugi of Yonezawa, and the Hachisuka of Awa. Initially, the Tokugawa regarded them as potentially rebellious, but for most of the Edo period, marriages between the Tokugawa and the tozama, as well as control policies such as sankin-k?tai, resulted in peaceful relations.
Daimy? were required to maintain residences in Edo as well as their fiefs, and to move periodically between Edo and their fiefs, typically spending alternate years in each place, in a practice called sankin-k?tai.
In 1869, the year after the Meiji Restoration, the daimy?, together with the kuge, formed a new aristocracy, the kazoku. In 1871, the han were abolished and prefectures were established, thus effectively ending the daimy? era in Japan. In the wake of this change, many daimy? remained in control of their lands, being appointed as prefectural governors; however, they were soon relieved of this duty and called en masse to Tokyo, thereby cutting off any independent base of power from which to potentially rebel. Despite this, members of former daimy? families remained prominent in government and society, and in some cases continue to remain prominent to the present day. For example, Morihiro Hosokawa, the former prime minister, is a descendant of the daimy? of Kumamoto.