Daimyo (, Daimy?, Japanese pronunciation: [daim?o:] ) were powerful Japanese magnates, feudal lords who, from the 10th century to the early Meiji period in the middle 19th century, ruled most of Japan from their vast, hereditary land holdings. They were subordinate to the sh?gun and nominally to the emperor and the kuge. 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 daimyo of the Edo period, the rank had a long and varied history. The backgrounds of daimyo also varied considerably; while some daimyo clans, notably the M?ri, Shimazu and Hosokawa, were cadet branches of the Imperial family or were descended from the kuge, other daimyo were promoted from the ranks of the samurai, notably during the Edo period.
Daimyo 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 daimyo era ended soon after the Meiji Restoration with the adoption of the prefecture system in 1871.
The shugo daimyo (?) were the first group of men to hold the title daimyo. They arose from among the shugo during the Muromachi period. The shugo-daimyo 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-daimyo 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-daimyo 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-daimyo. The deputies of the shugo-daimyo, living in the provinces, seized the opportunity to strengthen their position. At the end of the fifteenth century, those shugo-daimyo 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-daimyo, who arose from the ranks of the shugodai and jizamurai.
Among the sengoku daimyo (?) were many who had been shugo-daimyo, such as the Satake, Imagawa, Takeda, Toki, Rokkaku, ?uchi, and Shimazu. New to the ranks of the daimyo were the Asakura, Amago, Nagao, Miyoshi, Ch?sokabe, Hatano, and Oda. These came from the ranks of the shugodai and their deputies. Additional sengoku-daimyo such as the M?ri, Tamura, and Ry?z?ji arose from the jizamurai. 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-daimyo.
The Battle of Sekigahara in 1600 marked the beginning of the Edo period. Sh?gun Tokugawa Ieyasu reorganized roughly 200 daimyo 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 daimyo. Ieyasu also categorized the daimyo 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 daimyo, 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 daimyo took positions in the Edo shogunate, some rising to the position of r?j?. The fact that fudai daimyo could hold government positions, while tozama in general could not, was a main difference between the two.
Tozama daimyo 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.
Daimyo 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 daimyo, together with the kuge, formed a new aristocracy, the kazoku. In 1871, the han were abolished, and prefectures were established. In this year, around 200 daimyo returned their titles to the emperor, who consolidated their han into 75 prefectures. Their military forces were also demobilized, with the daimyo and their samurai followers pensioned into retirement. The move to abolish the feudal domains effectively ended the daimyo era in Japan. This was effectively carried out through the financial collapse of the feudal-domain governments, hampering their capability for resistance.
In the wake of the changes, many daimyo 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 daimyo 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 of Japan, is a descendant of the daimyo of Kumamoto.