Shirakawa Domain  The Shirakawa Barrier was noted from the Nara period as the border between the “settled” regions of Japan proper, and the “frontier” regions of northern Japan, and was of great strategic importance. During the Sengoku period, the area around Shirakawa was controlled by the rulers of Aizu. In 1627, Niwa Nagashige, one of Tokugawa Ieyasu’s generals, was transferred from Tanakura Domain to the newly established Shirakawa Domain, with a "kokudaka" of 100,700 "koku". He built Komine Castle, and established the surrounding castle town. He was followed by his son, Niwa Mitsushige in 1637, but the clan was transferred to Nihonmatsu Domain in 1647. The Niwa were replaced by Sasakibara Tadatsugu from Tatebayashi Domain, with an increase to 140,000 "koku". Tadatsugu’s mother was one of Ieyasu’s concubines, and for a time he adopted the Matsudaira surname. However, his tenure at Shirakawa was short, and he was transferred to Himeji Domain in 1649. The domain was then assigned to Honda Tadayoshi, formerly of Murakami Domain, and its size was reduced to 120,000 "koku". Tadayoshi placed strong efforts into the development of new rice lands, raising his actual revenues by an additional 15,000 "koku" . In the 1650-1651 period, his actual revenues were 37,000 "koku" higher than his official rating. However, this disparity and complaints from his subjects on harsh and excessive taxation, led to his son, Honda Tadahira, being transferred to Utsunomiya Domain in 1681. Shirakawa was then assigned to Matsudaira (Okudaira) Tadahiro, but he was in poor health and assigned running the domain to his "karō". Furthermore, the early death of his sons led to an "O-Ie Sōdō" which divided his retainers between a faction favoring a son-in-law and a faction favoring a grandson. His inability to resolve this crisis resulted in his demotion and replacement by another branch of the Matsudaira clan. Matsudaira (Echizen) Naonori became "daimyō" of Shirakawa in 1692 and initially implemented plans to repair the domain’s finances through fiscal restraint and reduction of the income of his retainers.