Lit.: "War of the Castle". The Otate no Ran was the name given to the intra-clan war fought between and , both adopted sons of , for succession to the position of head of the Uesugi Clan after Kenshin died. The war bifurcated the Uesugi commanders and in the end significantly weakened Uesugi's power. The "", or "Castle/Mansion" refers to the residence built for the , , near . He used it as a government office after Norimasa passed on the title to him and the lands around were developed.
On March 9th in the 6th year of (April 15th, 1578), collapsed at 's privy from an "unforeseen nervous weakness" (some speculate poison or assassination) and died on the 13th (April 19th, 1578) without ever regaining consciousness.
Traditionally, it is held that he died without ever deciding on an heir. Some point to evidence such as accompanying him on shrine visits at the New Year and not being forced to perform military service (though proof of the latter is sketchy), to support theories that Kenshin favored Kagetora. It is evident that Kagetora, who was adopted from the mighty Houjou Clan, ruler of the , had unshakeable standing within the Uesugi Clan even after the - Alliance fell apart in 1571.
On the other hand, Kenshin had conferred the highest military powers within the Uesugi family on Kagekatsu, and the Uesugi retainers used similar titles for Kenshin and Kagekatsu.
Pointing to some of the above reasons, many historians argue that Kenshin had intended to pass the title of and position of clan head of the Sannai-Uesugi Clan to Kagetora while making Kagekatsu the master of and the head of the Echigo-Uesugi Clan. There is no way of telling based on current evidence which would have been the sole heir.
In any case, a dispute over the rightful heir to Kenshin arose between Kagekatsu and Kagetora immediately. Kagekatsu moved first. On the day following Kenshin's death, , viewed as being in the Kagetora faction, was assassinated (there is another theory that Haruie was killed before the Otate no Ran, when his father was accused of treason). Also, according to one primary historical record, Kagekatsu moved quickly to occupy the inner citadel, treasury, and armory of , though the exact date is unknown. Kagekatsu proclaimed himself the rightful heir in a letter dated March 24th (April 30th) and began attacking Kagetora, barricaded in the Third Wing.
Kagekatsu and Kagetora's forces fought in what is now Jouetsu City on May 5th (June 10th, 1578), and until Kagetora evacuated in the middle of the month, hostilities continued within . During that time, both Kagekatsu and Kagetora tried to win the various generals to their side.
Commanders committed to Kagekatsu:
- : Oumi
- , ,
- :
- : Son of , master of Hirabayashi Castle
- : one of Kenshin's adopted sons, Kagekatsu's brother-in-law, head of the Joujou-Uesugi family
- :
-
- : Buzen
- : head of the Yamaura-Uesugi family
- : , master of
- : Harima
- : , master of Akada Castle
- , ,
-
- : head of the Yamayoshi Clan, master of Koba Castle
- : head of the -Yasuda Clan, master of Iiyama Castle
- : master of Yasuda Castle
- , ,
Commanders committed to Kagetora:
- : head of the Ashina Clan
- : master of Oobasawa Castle
- : head of the Daihouji Clan
- (who later betrayed him): , master of
- : master of Numata Castle
-
- , , : Kagetora's elder brothers, head and generals of the Houjou Clan
- : nephew of , master of Kaji Castle
- : master of Sanjou Castle
- : Houki
- ,
- : master of Kurokawa Castle
-
- : head of the Sanbonji-Uesugi Clan, master of Fudouzan Castle,
- : master of Jouhukuji Castle
- (who was later bribed by Kagekatsu and entered into an alliance with him): head of the Takeda Clan
- : Kenshin's adopted father, former
- : originally Nagao, head of the Koshin-Nagao family
- : son of
On May 13th (June 18th), with the lines between the commanders drawn, Kagetora finally retreated from the Third Wing to the and requested aid from his brother while ordering his troops to set fire to the lands around . He attacked with around 6000 troops on May 17th (June 22nd), but was repelled.
He regrouped and attacked again on the 22nd (June 27th) with the same result. Around this time, hostilities between Kagekatsu and Kagetora's forces also began within the broader region. In , and (father and son) sent forth troops with their aim on Kunohe Castle. Kagekatsu had no troops to spare at this point, and Kagetora's side easily took several castles in Miyano and Ogawa. Kagetora's side had completed organization for drawing Houjou troops into Echigo at this point, but since the distance was great, the Houjou requested assistance from their ally . Katsuyori sent an advance guard of 20,000 under the command of Takeda Nobutoyo, which arrived at the - border on May 29th (July 4th).
Aside from the Houjou and Takeda, Kagetora also received assistance from . However, Moritaka met dogged resistance from Kagekatsu's forces and was stopped in his tracks. Still, Kagetora held the advantage at this point. The only problem: Ujimasa had little interest in moving to the offensive.
Kagekatsu, at a disadvantage now that he was being attacked from three directions, took a big gamble. He sent an advance guard to Katsuyori's camp offering a large amount of money and 's rice fields in exchange for a Kagekatsu-Takeda alliance. How Kagekatsu knew that Katsuyori was painfully short on funds after his ignominious defeat at the Battle of Nagashino to and is unknown. Katsuyori arrived at and conferred with Nobutoyo. He entered into an alliance with Kagekatsu on June 12th (July 16th).
Now that Kagekatsu's side had successfully bought Takeda, they no longer needed to watch their backs. On the day the alliance was made Kagekatsu took Noumine Castle, allowing him to communicate with Sakato Castle from . On the following day, Kagetora's side lost , and their situation worsened day by day. Kagekatsu pressed towards various castles held by Kagetora's forces in . Katsuyori continued peace negotiations with Kagekatsu at full tilt; they were concluded on June 29th (August 2nd), and he withdrew his troops on August 28th (September 29th).
In the following month, Ujimasa finally began moving in earnest. and set out for by Ujimasa's command. They crossed and took , within striking distance of Sakato Castle. However, the castle was well-guarded by Kagekatsu's forces, and with the onset of winter the Houjou forces could not advance to Kasugayama.
Finally, with Ujikuni and Takahiro left behind to guard and Kagehiro acting as rear guard, they retreated. The Takeda forces, withdrawing from the lands around , loitered between Kasugayama/Otate and Sakato Castle, in the end acting as a deterrent against Kagetora and Houjou forces. At the end of the year (January in the Gregorian calendar) Kagekatsu married Katsuyori's younger sister.
Having skillfully removed external threats and gathered support within the clan, Kagekatsu decided that the internal war would be resolved before the snow thawed. On the other hand, Kagetora was losing both supporters and castles. On February 2nd (February 27, 1579) Kagekatsu ordered a general offensive against Kagetora at . Kagehiro was killed.
Kagekatsu recaptured from the Houjou. Kagetora escaped from and, with no hope of relief from the Houjou, who were blocked off by snow, sent his eldest son along with Kenshin's adopted father to negotiate for peace. On the way to Kagekatsu's camp, they were surrounded by Kagekatsu's troops and killed (there are accounts that the order actually came from ). On his flight from towards the , Kagetora stopped at . There he was betrayed by its master, , and committed suicide along with his family on March 24th (April 19th, 1579).
Though Kagekatsu won the internal war, he would continue to face resistance from , and others, and would not have total control of the clan until a year later.
The Otate no Ran would become one of the underlying reasons for the destruction of the Takeda Clan and the drastic decline of the Uesugi Clan's power.
<small>Note: Japanese dates given in this entry are based on the lunar calendar; Gregorian Calendar dates in () were calculated using <a href="http://www.uni-tuebingen.de/geschichte-japans/nengo_calc.htm">NengoCalc</a>.</small>