was a feudal domain under the Tokugawa shogunate of Edo period Japan, in what is now northern Okayama Prefecture. It controlled most of Mimasaka Province and was centered around Tsuyama Castle. It was ruled in its early history by a branch of the Mori clan, and later by a branch of the Matsudaira clan. Tsuyama Domain was dissolved in the abolition of the han system in 1871 and is now part of Okayama Prefecture. History In 1600, after the Battle of Sekigahara, Mimasaka Province was ruled by Kobayakawa Hideaki, the daimyō of Okayama Domain. However, his domain was abolished due to attainder on his death without heir in 1602. In 1603, the Tokugawa shogunate appointed Mori Tadamasa, the son of Mori Yoshinari of Kawanakajima Domain in Shinano Province and the younger brother of Oda Nobunaga's page Mori Ranmaru, to the newly-created Tsuyama Domain with a kokudaka of 186,000 koku. He changed the name of the area, which was originally called to "Tsuyama", began construction of Tsuyama Castle in 1604 and completed the layout of his castle town by 1616. In 1697, his 5th generation successor Mori Sugutoshi went insane in Ise Province on his way to Edo to fulfill his sankin kōtai duties. The "madness" may have been an excuse, as Sugutoshi had been in charge of constructing dog kennels outside Edo as part of Shogun Tokugawa Tsunayoshi's highly unpopular and ridiculed law against cruelty to animal and Sugutoshi reportedly fell into a rage on hearing that a ronin had broke into the kennel, slaughtering many dogs, which had resulted in the shogunate ordering the execution of a number of his retainers for negligence. The domain was reduced to 100,000 koku, and transferred to a branch of the Echizen-Matsudaira clan whose ancestor was Yūki Hideyasu. In 1721, the second daimyō, Matsudaira Asagoro died at the age of 11 without heir. The shogunate agreed to allow a younger son of the daimyō of Shirakawa Nitta Domain to be posthumously adopted to secure the succession, but the kokudaka of the domain was halved to 50,000 koku. The prestige and also the ability of the domain to support its retainers was thus severely restricted, and the domain thereafter suffered from political and economic instability and frequent peasant uprisings. In 1765, the 5th daimyō, Matsudaira Yasuchika, opened a han school, the Kakuzankan (鶴山館), which lasted into the early Meiji period. The domain managed to