The was a Japanese

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 clan which came to prominence during 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...

. Its origins were in Kōzuke Province

Kozuke Province

was an old province located in the Tōsandō of Japan, which today comprises Gunma Prefecture. It is nicknamed as or .The ancient provincial capital was near modern Maebashi. During the Sengoku period, Kōzuke was controlled variously by Takeda Shingen, Uesugi Kenshin, the late Hōjō clan, and...

; however, members of the family moved to 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....

 and served the Matsudaira clan

Matsudaira clan

The was a Japanese samurai clan that claimed descent from the Minamoto clan. It first originated in and took its name from Matsudaira village, in Mikawa Province . Over the course of its history, the clan produced many branches, most of which also centered around Mikawa Province...

 (later known as the Tokugawa clan

Tokugawa clan

The was a powerful daimyo family of Japan. They nominally descended from Emperor Seiwa and were a branch of the Minamoto clan by the Nitta clan. However, the early history of this clan remains a mystery.-History:...

). The Aoyama became a daimyo family during 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 Aoyama clan held the Sasayama Castle

Sasayama Castle

is a Japanese castle in Sasayama, Hyōgo, Japan.-History:Construction of this castle was begun by the order of Tokugawa Ieyasu in 1608 and it was completed in six months. Ikeda Terumasa was in charge of the construction and the plan of the castle was done by Tōdō Takatora. It is said that twenty...

, located at Sasayama

Sasayama, Hyogo

is a city located in the central eastern part of Hyōgo Prefecture, Japan.The city was established on April 1, 1999, merging the towns of the former "Taki District" ....

, Hyōgo Prefecture

Hyogo Prefecture

is a prefecture of Japan located in the Kansai region on Honshū island. The capital is Kobe.The prefecture's name was previously alternately spelled as Hiogo.- History :...

, for 123 years during the Edo period. The first Aoyama lordship of the castle started in 1748, and continued until the castle was torn down in 1871.