The Rokkaku clan (六角氏 Rokkaku-shi) was a Japanese clan in Ōmi province.
Rokkaku Clan History
Founded by Sasaki Yasutsuna of Ōmi province in the 13th century, the name Rokkaku was taken from their residence in Kyoto; however, many members of this family continued to be called Sasaki.
During the Muromachi period, members of the clan held the high office of shugo in various provinces.
During the Ōnin War (1467-77), the end of which marked the beginning of the Sengoku period, Kannonji Castle, the clan's stronghold, came under siege. After the defeat, the clan entered a period of slow decline.
Like other daimyō under constant threat from neighboring clans, the Rokkaku sought to improve their military strength by paying more attention to improving civil administration within their domain.
For example, in 1549, the Rokkaku eliminated a merchant guild in Mino and confiscated their property. So in their place they declared a free market.
The Rokakku clashed with the Azai clan and were defeated by Oda Nobunaga in 1568 during his march to Kyoto. In 1570 they were finally defeated by Shibata Katsuie in the siege of Chōkō-ji and lost their status as daimyō.
During the Edo period, the descendants of Rokkaku Yoshisuke became kōke.
Prominent members of the Rokkaku Clan
- Rokkaku Yasutsuna (泰綱; 1213-1276) Son of Sasaki Nobutsuna (1181-1242), he was the first to be called Rokkaku in the late 13th century, a name taken from the residence in Kyoto where he lived.
- Rokkaku Ujiyori (氏頼; 1326-1370) A great-grandson of Yasutsuna he was also Shugo and Kebiishi. He joined the Northern court during the Nanboku-chō period and fought in the ranks of Ashikaga Takauji and Ashikaga Yoshiakira. Ujiyori resided in Kannonji Castle which had been built by his ancestors.
- Rokkaku Mitsutaka (満高; 1369-1416) According to some sources he was the son of shōgun Ashikaga Yoshiakira, was adopted by Ujiyori and inherited his title.
- Rokkaku Takayori (高頼; 1462-1520) Mitsutaka's great-grandson sided with Yamana Sōzen during the Ōnin War in 1467 and conquered the entire province of Ōmi from Kyōgoku, the other branch of the Sasaki family. In 1487 Takayori was besieged by Shōgun Ashikaga Yoshihisa in his Kannonji castle and fled to Kōya Monastery. Yoshihisa died during the siege and was replaced by Ashikaga Yoshitane who took up arms again in 1492. Takayori was defeated and forced to flee. At the death of the emperor Go-Tsuchimikado paid all the expenses for the funeral and as a reward, in 1500, he obtained permission to add the imperial chrysanthemum and paulownia to his coat of arms. When the shōgun Ashikaga Yoshizumi was driven out of Kyoto by his rival Ashikaga Yoshitane he sought protection from Takayori.
- Rokkaku Sadayori (定頼; 1495-1552) Son of Takayori, he was initially a monk at the Shōkoku-ji temple. When his older brother Ujitsuna (氏 綱, 1518) died, he inherited the leadership of the clan. He contributed in the victory of Ōuchi Yoshioki (内 義興, 1477-1528) in 1511 over Hosokawa Masakata and then became kanrei (Deputy Governor General of the Shogun). In 1518 he unsuccessfully besieged Azai Sukemasa in his castle at Odani. Shortly afterwards he gathered his troops and marched, in 1520, to Kyoto and drove out Miyoshi Nagateru and Hosokawa Sumimoto. He died fighting against the Miyoshi clan.
- Rokkaku Yoshikata (義賢; 1521-1598) Sadayori's son assisted Hosokawa Harumoto (細 川 晴 元; 1514-1563) in 1549 in his fight against Miyoshi Chōkei (三好 長慶; 1522-1564). In 1555 he tried to conquer part of Ise province and besieged Chikusa Castle, but Chikusa Tadahara was able to negotiate a peace. Later Yoshikata fought against Matsunaga Hisahide at the Nyoi -ga-mine pass (Yamashiro province) and moved in 1558 with shōgun Ashikaga Yoshiteru to Kyoto. In 1562 he made peace with Miyoshi Chōkei, leaving his son Yoshiharu to administer his estates. Yoshitaka shaved his head and became a Buddhist monk, changing his name to Shōtei.
- Rokkaku Yoshiharu/Yoshisuke (義治/義弼; 1545-1612) Son of Yoshikata took control in 1562 of his father's lands, supported by Gamō Katahide (蒲 生 賢 秀, 1534-1584). In 1565, after the assassination of the shōgun Yoshiteru, his brother, the monk Gakkei, asked him to assert his rights in the shogunate. But Yoshisuke dared not go against the powerful Miyoshi clan. Then Gakkei contacted Oda Nobunaga who accepted the request, set up an army and marched on Kyoto. In the province of Ōmi he conquered some castles of the Rokkaku, so that Yoshisuke eventually had to take refuge in the monastery of Kōya. Yoshisuke was then besieged in 1572 by Shibata Katsuie in his Namazue castle and had to surrender, lost all his possessions, and lived in Nobunaga's court ever since. One of his descendants was the mathematician Kikuchi Dairoku.