was a samurai of 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...

, and the third son of Hōjō Ujiyasu

Hojo Ujiyasu

was the son of Hōjō Ujitsuna and a daimyō of the Odawara Hōjō clan.Upon his father's death in 1541, a number of the Hōjō's enemies sought to take advantage of the opportunity to seize major Hōjō strongholds...

. Ujikuni was a high ranking commander in the invasion of Kozuke

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...

. He was also the castellan

Castellan

A castellan was the governor or captain of a castle. The word stems from the Latin Castellanus, derived from castellum "castle". Also known as a constable.-Duties:...

 (castle lord) in command of Hachigata Castle

Hachigata Castle

is a mountain castle, or yamashiro, located in Yorii, Saitama Prefecture, Japan.-History:Hachigata Castle was built in approximately 1476 by Nagao Kageharu of the Late Hōjō clan. The castle was constructed at an excellent location, as it oversaw much traffic at an important crossroads, and was...

 in Musashi province

Musashi Province

was a province of Japan, which today comprises Tokyo Prefecture, most of Saitama Prefecture and part of Kanagawa Prefecture. It was sometimes called . The province encompassed Kawasaki and Yokohama...

, which came under siege twice, in 1568

Siege of Hachigata (1568)

The first siege of Hachigata took place in 1568; Takeda Shingen laid siege to the castle, which was controlled by Hōjō Ujikuni, but was unable to capture it. Shingen then moved south to besiege Takiyama castle, on his way to the Hōjō capital of Odawara....

 and in 1590

Siege of Hachigata (1590)

The 1590 siege of Hachigata was the penultimate battle of Toyotomi Hideyoshi's campaigns against the Hōjō clan, during Japan's Sengoku period...

.

After losing his castle 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...

, Ujikuni aided in the defense of the Hōjō's central home castle, Odawara

Odawara Castle

is a landmark in the city of Odawara in Kanagawa Prefecture, Japan.-History:Odawara was a stronghold of the Doi clan during the Kamakura period, and a fortified residence was built by their collateral branch, the Kobayakawa clan stood on the approximate site of the present castle...

. The Siege of Odawara

Siege of Odawara (1590)

The third ' occurred in 1590, and was the primary action in Toyotomi Hideyoshi's campaign to eliminate the Hōjō clan as a threat to his power. The months leading up to it saw hasty but major improvements in the defense of the castle, as Hideyoshi's intentions became clear...

would be the Hōjō's final stand and marks the end of their power and prominence.