The great lords of the feudal period, 1185 to 1868. The word came from dai meaning 'great' and myo, part of the word for private fields. By the 16th century, hundreds of daimyo dominated Japan; political or military struggles for power were almost constant. In the next century, one of the daimyo, Tokugawa Ieyasu, asserted dominance. During the next 250 years, daimyo remained individually independent within their domains, but subject to the authority of the Tokugawa shogunate. The definition of a daimyo in this period was that he have an income of over 10,000 koku (one koku equals approximately 5 bushels) of rice. In return for land, the daimyo owed his lord military service. The personal power of the daimyo was diminished during the Edo period as government became more bureaucratic.