was a daimyo

Daimyo

is a generic term referring to the powerful territorial lords in pre-modern Japan who ruled most of the country from their vast, hereditary land holdings...

 during the Sengoku

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 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....

s of Japanese history

History of Japan

The history of Japan encompasses the history of the islands of Japan and the Japanese people, spanning the ancient history of the region to the modern history of Japan as a nation state. Following the last ice age, around 12,000 BC, the rich ecosystem of the Japanese Archipelago fostered human...

. The son of Nagao Masakage

Nagao Masakage

was the head of the Ueda Nagao clan following the Sengoku period of the 16th century of Japan. Masakage was the brother-in-law of the famous Uesugi Kenshin, the "Dragon of Echigo". Masakage was the father of Uesugi Kagekatsu....

 (the head of the Ueda Nagao

Nagao

The ' was a family of daimyo, feudal lords who built and controlled Kasugayama Castle and the surrounding fief, in what is now Niigata Prefecture. Nagao Kagetora, adopted by Uesugi Norimasa, became lord of the castle in 1548, taking the name Uesugi Kenshin and effectively changing the ruling clan...

 clan) and husband of Uesugi Kenshin

Uesugi Kenshin

was a daimyo who ruled Echigo province in the Sengoku period of Japan.He was one of the most powerful lords of the Sengoku period. While chiefly remembered for his prowess on the battlefield, Kenshin is also regarded as an extremely skillful administrator who fostered the growth of local industries...

's elder sister, Aya-Gozen

Aya-Gozen

' was the older half-sister of Uesugi Kenshin, the mother of Uesugi Kagekatsu and the first wife of Nagao Masakage.Born as Nagao Tamekage's second eldest daughter. She was said to either come from the same mother as Uesugi Kenshin or was his older half-sister...

. After his father died, he was adopted by Kenshin.
Upon Kenshin's death in 1578, Kagekatsu battled Kenshin's other adopted son Uesugi Kagetora

Uesugi Kagetora

was the seventh son of Hōjō Ujiyasu; he was adopted by Uesugi Kenshin, and was meant to be Kenshin's heir. However, in 1578, he was attacked in his castle at Ōtate by Uesugi Kagekatsu--Kagetora's respective brother-in-law—and was subsequently defeated. Kagetora committed suicide the following...

 for the inheritance, defeating him in the 1578 Ōtate no Ran. He forced Kagetora to commit seppuku, and became head of the Uesugi clan

Uesugi clan

The was a Japanese samurai clan, descended from the Fujiwara clan and particularly notable for their power in the Muromachi and Sengoku periods ....

. Kagekatu was married with Takeda Katsuyori

Takeda Katsuyori

was a Japanese daimyo of the Sengoku Period, who was famed as the head of the Takeda clan and the successor to the legendary warlord Takeda Shingen. He was the son of Shingen by the , the daughter of Suwa Yorishige...

's sister (Takeda Shingen

Takeda Shingen

, of Kai Province, was a preeminent daimyo in feudal Japan with exceptional military prestige in the late stage of the Sengoku period.-Name:Shingen was called "Tarō" or "Katsuchiyo" during his childhood...

's daughter) after Ōtate no Ran.

As a general under 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...

, Kagekatsu took part in the 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...

 and Korea campaigns, and rose to prominence to become a member of the council of Five Elders

Council of Five Elders

The council of five elders, also known as the five Tairō , was formed by Toyotomi Hideyoshi to rule Japan in the place of his son, Hideyori, until such time as he came of age. Hideyoshi chose his five most powerful daimyo: Ukita Hideie, Maeda Toshiie, Uesugi Kagekatsu, Mōri Terumoto, and the...

. Originally holding a 550,000 koku

Koku

The is a Japanese unit of volume, equal to ten cubic shaku. In this definition, 3.5937 koku equal one cubic metre, i.e. 1 koku is approximately 278.3 litres. The koku was originally defined as a quantity of rice, historically defined as enough rice to feed one person for one year...

fief in Echigo province

Echigo Province

was an old province in north-central Japan, on the shores of the Sea of Japan. It was sometimes called , with Echizen and Etchū Provinces. Today the area is part of Niigata Prefecture, which also includes the island which was the old Sado Province. This province was the northernmost part of the...

, Kagekatsu received the fief of Aizu

Aizu

is an area comprising the westernmost third of Fukushima Prefecture in Japan. The principal city of the area is Aizuwakamatsu.During the Edo period, Aizu was a feudal domain known as and part of Mutsu Province.-History:...

, worth a huge 1.2 million koku when Hideyoshi redistributed holdings in 1598. After Hideyoshi's death, that year, Kagekatsu then allied himself with Ishida Mitsunari

Ishida Mitsunari

Ishida Mitsunari was a samurai who led the Western army in the Battle of Sekigahara following the Azuchi-Momoyama period of the 17th century. Also known by his court title, Jibunoshō...

, against 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...

, as the result of some political dispute.

The Sekigahara Campaign could be said to have begun, at least in part, with Kagekatsu, who was the first daimyo to plan revolt against the Tokugawa. He built a new castle in Aizu, attracting the attention of Ieyasu, who ordered him to Osaka, to explain his conduct. Kagekatsu refused, and Tokugawa began plans to lead a 50,000 man army north against him. Ishida and Uesugi hoped to occupy Tokugawa Ieyasu with this fighting in the north, distracting him from Ishida Mitsunari's attacks in and around Osaka

Osaka

is a city in the Kansai region of Japan's main island of Honshu, a designated city under the Local Autonomy Law, the capital city of Osaka Prefecture and also the biggest part of Keihanshin area, which is represented by three major cities of Japan, Kyoto, Osaka and Kobe...

. Anticipating this, Ieyasu remained in Osaka to engage Mitsunari; his generals Mogami Yoshiaki

Mogami Yoshiaki

was a daimyō of the Yamagata domain in Dewa Province, in the late Sengoku period and early Edo period.-Life:Mogami Yoshiaki was the first son of Mogami Yoshimori , and succeeded his father as daimyō of Yamagata...

 and Date Masamune

Date Masamune

was a regional strongman of Japan's Azuchi-Momoyama period through early Edo period. Heir to a long line of powerful daimyo in the Tōhoku region, he went on to found the modern-day city of Sendai...

 would fight Kagekatsu in Tōhoku (the far north-east of Honshū, Japan's main island). Kagekatsu had intended to move his force south, attacking the Tokugawa from the north-east while Ishida attacked from the west, but he was defeated very early in the campaign, at the siege of his castle at Shiroishi

Siege of Shiroishi

The siege of Shiroishi, in 1600, was one of several feudal Japanese battles leading up to the decisive battle of Sekigahara which ended the period of over 100 years of war, and was immediately followed by the establishment of the Tokugawa shogunate...

.

Declaring his allegiance to Tokugawa following his defeat, Kagekatsu became a tozama

Tozama

A ' was a daimyo who was considered an outsider by the rulers of Japan. The term came into use in the Kamakura period and continued until the end of the Edo period.-Edo period:...

(outsider) daimyo; he was given the Yonezawa han

Yonezawa Domain

Yonezawa Domain was a feudal domain of Tokugawa Japan, controlled by daimyō of the Uesugi clan. Covering the Okitama district of Dewa province, in what is today southeastern Yamagata Prefecture, the territory was ruled from Yonezawa castle in Yonezawa city...

, worth 300,000 koku, in the Tōhoku region. Kagekatsu would later fight for the Tokugawa shogunate against the Toyotomi clan

Toyotomi clan

Originating in Owari Province, the served as retainers to the Oda clan throughout 16th-century Japan's Sengoku period. -Unity and Conflict:The most influential figure within the Toyotomi was Toyotomi Hideyoshi, one of the three "unifiers of Japan." Oda Nobunaga was another primary unifier and the...

 in the 1614-15 siege of Osaka

Siege of Osaka

The was a series of battles undertaken by the Tokugawa shogunate against the Toyotomi clan, and ending in that clan's destruction. Divided into two stages , and lasting from 1614 to 1615, the siege put an end to the last major armed opposition to the shogunate's establishment...

.