In 1642, Matsudaira Yorishige, the eldest son of Tokugawa Yorifusa, of Mito Domain, and daimyō of Shimodate Domain in Hitachi Province was transferred to Takamatsu Castle and given a fief of 120,000 koku, in eastern Sanuki. It is said that Yorishige was given this position at the express request of his cousin, ShogunTokugawa Iemitsu, with whom he was on very good terms. Although they were cousins, Yorishige was allowed free access to the Shogun's private chambers in Edo Castle and he was given the honor of being seated (along with the Ii clan and the Aizu Matsudaira clans closest to the shogun during official councils. This allowed him to be able to listen to the political reports of the chief minister, and although prohibited from giving publicly giving opinions or intervening in politics, made him a major political figure within the Tokugawa shogunate. The location of Takamatsu was of great strategic importance and allowed Matsudaira Yorishige to monitor the movements of the domains in the western part of Japan on behalf of the shogunate. Thus, although the Takamatsu-Matsudaira family was a cadet branch family of the Mito-Tokugawa family, but they were not in a position to receive instructions from the Mito Domain and were highly independent. However, the domains remained bound closely together. Tokugawa Mitsukuni, the second daimyō of Mito appointed Yorishige's second son as his heir, and sent his own son, Yoritsuna, to succeed Takamatsu Domain. This "exchange of heirs" took place several times over the domain's history, resulting in the last Shogun, Tokugawa Yoshinobu being a direct descendant of Matsudaira Yorishige.
The Matsudaira rulers of Takamatsu placed great emphasis on land improvement through building reservoirs, and reclaiming land along the coastline to develop new rice fields and salt fields. They also diverted the flow of the Koto River, which used to run through the center of Takamatsu, to the west for irrigation purposes and improved the water supply for Takamatsu Castle. The domain also encouraged production of lacquerware and pottery as local industries. The han school, Kodokan, produced numerous scholarly figures in the Edo Period, including Hiraga Gennai. Many of the Matsudaira daimyō excelled in academics, poetry, and the Japanese tea ceremony. Some gave lectures on Neo-Confucianism to the shogun. The 5th daimyōMatsudaira Yoriyasu, had a medicinal herb garden (now Ritsurin Park) built in line with Shogun Tokugawa Yoshimune's policy of encouraging research into domestic production of medicines and agricultural products. In addition, he developed the manufacturing technology for "Sanuki wasanbon" sugar, which is still one of Kagawa's specialty products. The ninth daimyō, Matsudaira Yoritsugu, developed Japan's largest salt field on the beach of Sakaide. During the Edo period, the Takamatsu Domain was the largest producer of white sugar and salt in Japan.
During the Bakumatsu period, Mito Domain came out strongly in support of the Sonnō jōi movement, placing it at odds with the shogunate and also politically with Takamatsu Domain. In addition the two domains were at odds during the succession issue over the successor to Shogun Tokugawa Iesada, and the bad relations between Takamatsu and Mito continued for over a hundred years to 1974 when the two cities officially reconciled. During the Battle of Toba-Fushimi in the Boshin War, Takamatsu Domain supported the shogunate and was initially labelled an "enemy of the court". A punitive force led by Tosa Domain and supported by Marugame and Tadotsu Domains was sent attack Takamatsu, but Tokushima Domain was reluctant and encouraged Takamatsu to defect. As a result, Matsudaira Yoritsuna was forced to retire and was placed under house arrest in Edo and two chief karō, Oga Mataemon and Obu Hyōgo, were ordered to commit seppuku, and the domain ordered to pay 120,000 ryō to the Meiji government. However, there was much anti-government sentiment in the domain, and in 1871 with the abolition of the han system, the domain's territory was initially merged with Tokushima and Ehime Prefectures, only becoming part of Kagawa Prefecture on December 3, 1888. Matsudaira Yoritoshi, the final daimyō of Takamatsu was later granted the kazoku peerage title of Count (hakushaku)
As with most domains in the han system, Takamatsu consisted of several discontinuous territories calculated to provide the assigned kokudaka, based on periodic cadastral surveys and projected agricultural yields.[5][6]
