The was a Japanese family which claimed descent from Minamoto no Yoshiie

Minamoto no Yoshiie

Minamoto no Yoshiie , also known as Hachimantarō, was a Minamoto clan samurai of the late Heian period, and Chinjufu shogun...

. They took their name from the Ishikawa district of Kawachi Province

Kawachi Province

was a province of Japan in the eastern part of modern Osaka Prefecture. It originally held the southwestern area that was split off into Izumi Province...

. In the Sengoku Period

Sengoku period

The or Warring States period in Japanese history was a time of social upheaval, political intrigue, and nearly constant military conflict that lasted roughly from the middle of the 15th century to the beginning of the 17th century. The name "Sengoku" was adopted by Japanese historians in reference...

, the family had two major branches; one of them, which had settled in Mikawa Province

Mikawa Province

is an old province in the area that today forms the eastern half of Aichi Prefecture. It was sometimes called . Mikawa bordered on Owari, Mino, Shinano, and Tōtōmi Provinces....

 in the 15th century, was a family of retainers serving what became the Tokugawa clan. Ishikawa Kazumasa

Ishikawa Kazumasa

Ishikawa Kazumasa, a very notable retainer under Tokugawa Ieyasu, even serving him since his childhood, since they were both hostages under the Imagawa at that time....

, one of Tokugawa Ieyasu

Tokugawa Ieyasu

 was the founder and first shogun of the Tokugawa shogunate of Japan , which ruled from the Battle of Sekigahara  in 1600 until the Meiji Restoration in 1868. Ieyasu seized power in 1600, received appointment as shogun in 1603, abdicated from office in 1605, but...

's senior retainers, was famous in his era for suddenly leaving Tokugawa service and pledging loyalty to Toyotomi Hideyoshi

Toyotomi Hideyoshi

was a daimyo warrior, general and politician of the Sengoku period. He unified the political factions of Japan. He succeeded his former liege lord, Oda Nobunaga, and brought an end to the Sengoku period. The period of his rule is often called the Momoyama period, named after Hideyoshi's castle...

. However, as Kazumasa's son Yasunaga became implicated in the Ōkubo Yasunaga incident, his branch of the Ishikawa of Mikawa came to an end then. The Mikawa-Ishikawa line continued through Kazumasa's uncle Ienari, Ienari's descendants eventually came to rule the Ise-Kameyama Domain

Ise-Kameyama Domain

The ' was a domain of the Edo period in Japan. It was located in Ise Province and had its headquarters and Kameyama Castle, which is in the modern-day city of Kameyama, Mie Prefecture....

 for most of the Edo period

Edo period

The , or , is a division of Japanese history which was ruled by the shoguns of the Tokugawa family, running from 1603 to 1868. The political entity of this period was the Tokugawa shogunate....

.

The other branch of the family, which had established itself in Kawachi Province

Kawachi Province

was a province of Japan in the eastern part of modern Osaka Prefecture. It originally held the southwestern area that was split off into Izumi Province...

, was the ancestor of the Nakagawa clan, which ruled the Oka Domain for the entirety of the Edo period

Edo period

The , or , is a division of Japanese history which was ruled by the shoguns of the Tokugawa family, running from 1603 to 1868. The political entity of this period was the Tokugawa shogunate....

.