, also known as Matsudaira Keiei, or better known as Matsudaira Shungaku (春嶽) was a Japanese daimyō of the Edo period. He was head of the Fukui Domain in Echizen Province. He is counted as one of the , along with Date Munenari, Yamauchi Yōdō and Shimazu Nariakira. "Yoshinaga" is his imina and "Shungaku" (春嶽, "Spring Mountain") is his gō. Early life He was born in Edo Castle as the eighth son of Tokugawa Narimasa, head of the Tayasu-Tokugawa, one of the gosankyō cadet branches of the Tokugawa clan. His childhood name was "Kin-no-jo" (錦之丞). He was designated to be adopted to Matsudaira Katsuyoshi, the daimyō of Iyo-Matsuyama Domain even before he was born, and it was officially announced on November 25, 1837. However, on July 27, 1838, Matsudaira Narisawa, the young daimyō of Fukui Domain suddenly died without heir. His sister, Asahime (matsudaira narisawa's predecessor's widow) and his brothers, Tokugawa Nariyoshi and Shōgun Tokugawa Ieyoshi agreed to have Kin-no-jo became the next daimyō of Fukui. After his genpuku ceremony, he took the name of "Matsudaira Yoshinaga", having been granted a kanji from the name of Shogun Tokugawa Ieyoshi. At this time, he was At that time, granted court rank of Senior Fourth Rank, Lower Grade and his courtesy title was Echizen-no-kami and Sakon'e-no-gonshōjō. On April 6, 1839, he was married to Yu-hime, a daughter of Hosokawa Narimori of Kumamoto Domain. As a Local Ruler In 1839, he began implementation of a fiscal austerity plan in an effort to resolve the perennial financial difficulties of Fukui Domain. He began by cutting the stipends for all of his samurai retainers in half for a three-year period, and also his own expenses for five years. In January 1840, with the discharge of Matsudaira Shume reformists such as Nakane Yukie, Yuri Kimimasa and Hashimoto Sanai took a leading role in domain politics. Yoshinaga performed innovative work such as establishment of a translation bureau "Yoshō-shūgaku-sho" to acquire rangaku knowledge and spur military modernisation. He built a modern armaments factory, and the Meidōkan han school was nationally recognised. A bussan-shokaijō, or cooperative venture been the domain and rich merchants also contributed to the domain's economic recovery. In 1851, he was promoted to Sakon'e-no-gonchūjō and Senior Fourth Rank, Upper Grade. Participation to the National Affairs In 1853, in the aftermath of the Perry Expedition to demand an end to Japan's national isolation policy, at first Yoshinaga