Founded by Sasaki Yasutsuna of Ōmi Province in the 13th century, the name Rokkaku was taken from their residence within Kyoto; however, many members of this family continued to be called Sasaki. Over the course of the Muromachi period, members of the clan held the high post of Constable (shugo) of various provinces.
During the Ōnin War (1467–77), which marked the beginning of the Sengoku period, the clan's Kannonji Castle came under assault. As a consequence of defeat in the field, the clan entered a period of decline.
Like other hard-pressed daimyōs, the Rokakku tried to enhance their military position by giving closer attention to improved civil administration within their domain. For instance, in 1549, the Rokkaku eliminated a paper merchant's guild in Mino under penalty of confiscation. Then they declared a free market in its place.[2]
During the Sengoku period, Japan's social and legal culture evolved in ways unrelated to the well-known history of serial battles and armed skirmishes. A number of forward-looking daimyos independently promulgated codes of conduct to be applied within a specific han or domain. Few examples of these daimyo-made law codes have survived, but the legal framework contrived by the Rokkaku clan remains amongst the small number of documents which can still be studied:
Rokkaku Yoshikata, 1521–1598—son of Sadayori; founder of Sasaki-ryū of martial arts.
Rokkaku Yoshiharu, 1545–1612—eldest son of Yoshikata. In 1562, he took on responsibilities in the administration of his father's domain. Later, he entered Ieyasu's service, and his descendants were ranked amongst the kōke. These included the Mitsukuri (箕作) family, notable doctors (who held the position of personal physician to the Matsudaira daimyōsofTsuyama, Mimasaka Province (modern-day Okayama Prefecture) who took their name from Mitsukuri castle, held by the Rokkaku family, and of whom a notable member was the statesman and scholar Mitsukuri Rinsho. Another descendant was the mathematician Kikuchi Dairoku.
Rokkaku Yoshisada, 16th Century—son of Yoshikata, younger brother of Yoshiharu.
^Sansom, George. (1961). 'A History of Japan: 1334–1615, p. 300.
^ abKatsumata Shizuo et al. (1981). "The Development of Sengoku Law" in Japan Before Tokugawa: Political Consolidation and Economic Growth, 1500 to 1650, p. 102.
