Hojo Soun (2/2)The foundation of the 5th generation of the Gohojo clan

Kiyoaki returned to secular life and took the name Yoshito (later changed his name to Yoshizumi). It is said that Yoshitsune, who came to power, ordered Sozui, who had a background as a shogunate bureaucrat and had a castle near Chachamaru, to avenge his mother and younger brother. In response to this, in the summer or fall of the same year, they attacked the Chachamaru of the Izu Horikoshi Imperial Palace, and Izu's powerful clans, including Suzuki Shigenmune and Matsushita Saburoemon, quickly gathered together.
This incident is called the Izu Raid, and it is believed that the Sengoku period began in the eastern part of Japan from this time.

Chachamaru is said to have committed suicide in military chronicles, but in historical records he escaped from the Horikoshi Imperial Palace and was supported by the Takeda, Sekito, Kano, and Doi clans, resisting the Ise clan for several years.

Sozui gradually cornered the Chachamaru side while gaining allies from the Izu people, captured Fukane Castle (Shimoda City) in southern Izu in August 1498, and finally conquered Izu after five years.
While subduing Izu, Sozui, as a military commander of the Imagawa clan, commanded the soldiers of the Imagawa clan from around 1494 and invaded Totomi, conquering as far as Chuto. Sozui will continue to expand his territory in cooperation with Ujichika.

Capturing Odawara Castle

In 1494, the conflict between the Yamauchi Uesugi family and the Ogidani Uesugi family (Chokyo War) reignited in the Kanto region, and Sadamasa Uesugi of the Ogidani family asked Sozui for reinforcements. On the side of Ogidani, Sozui faced the army of Kensada Uesugi, head of the Yamauchi family and Kanto Kanrei, at Arakawa, but withdrew after Sadamasa fell from his horse and died.

The Ogiya family was supported by the Miura and Omori clans of Sagami, but in this year three of their respective heads, Sadamasa Ogiya, Tokitaka Miura, and Ujiyori Omori, died. Sozui invaded Kai in 1495, using the subjugation and search for Chachamaru as his cause, and fought against the Kai shogun, Takeda Shinnawa. In September of the same year, he defeated Fujiyori Omori of Sagami-Odawara and captured Odawara Castle.

In 1498, Sozui succeeded in capturing Chachamaru in Kai and killing him. There is also a theory that the place where Chachamaru was killed was Fukane Castle in Izu Province. The Imagawa clan's activities as military commanders continued, reaching Mikawa in the Bunki era (1501 – 1504).

After that, they made a full-fledged move toward Sagami and began conquering the southern Kanto region, but Uesugi Kensada of the Yamauchi family, who had lost Izu and Nishi-Sagami, approached Yoshizumi and Masamoto, making Ujichika and Sozui's political position weak. Become. Furthermore, as Masamoto attempted to coordinate Kensada with Yoshihiro Shiba, the governor of Totomi Province, who had a conflicting relationship with the Imagawa clan, he was forced into a disadvantageous situation, as there was a risk of a pincer attack between the two parties.
Still, Ujichika and Sozui sided with the Yoshitane-Ouchi camp and gradually expanded their influence in Sagami.

In 1507, Kanrei Hosokawa Masamoto was assassinated by his adopted son, Hosokawa Sumiyuki, who resented his exclusion, resulting in the Eisho Confusion. Immediately afterward, an incident occurred in which Echigo Shugo Fusano Uesugi, who had been allied with Masamoto, was killed by Tamekage Nagao (father of Uesugi Kenshin), who was the Shugo, and Yoshitane Ashikaga, who took advantage of the change in Masamoto's power, In 1508, he returned to Kyoto with Yoshioki Ouchi's army in pursuit of Yoshizumi.

As a result of these moves, Ujichika and Sozui were no longer under pressure from the Muromachi shogunate, and Sozui joined forces with Tamekage and Kageharu Nagao to keep Kensada in check.

After 1509, the Imagawa clan's activities as military commanders were almost absent, and they concentrated on advancing to Sagami. In July of the same year, Kensada led a large army to Echigo, and in August of the same year, Sozui took advantage of this opportunity and approached Edo Castle, the home base of the Ogidani Uesugi family.

Chora Ogiya, who had gone to Ueno, returned his troops and fought in Musashi and Sagami until the following year, 1510. Sozui forced Masamori Ueda of Gongen Yamashiro (Kanagawa Ward, Yokohama City) to defect from the Ogidani family, but in July of the same year, the Ogidani family, with reinforcements from the Yamauchi family, counterattacked, Gongen Yamashiro fell, and Miura Gido (Dochi) Sozui was able to survive by making peace with the Ogitani family as the Ise clan captured the Sumiyoshi stronghold (Hiratsuka City) and approached Odawara Castle.

Meanwhile, on June 20th of the same year, Akisada, who had gone to Echigo, was defeated in a counterattack by Tamekage Nagao, and after his death, a conflict broke out between his two adopted children, Akizumi and Norifusa, and even in the Koga Kubo family, Ashikaga A conflict broke out between the political clan, Takamoto, and his son, and Asara was busy mediating these conflicts (Eisho War).

The Miura clan was a prominent Sagami clan that participated in Minamoto no Yoritomo's raising of an army and had great influence as a worthy vassal of the founding of the Kamakura shogunate, but their direct line was destroyed by the regent Hojo clan in the Battle of Hoji. However, a branch of the clan continued as a powerful clan in Sagami and had great power in Sagami (the Sagami Miura clan).

At this time, the Miura clan belonged to the Ogitani family, and the head of the family, Yoshitoshi (Dosun), was based at Okazaki Castle (now Isehara City) in central Sagami, and Arai Castle or Misaki Castle (now Miura City) on the Miura Peninsula. ) is protected by the child's righteousness.

Sozui, who had recovered from his defeat, captured Okazaki Castle in August 1512, and routed Gido to Sumiyoshi Castle (Zushi City). He escapes to Misaki Castle, protected by Yoshii. Sozui occupied Kamakura and gained control of Sagami.

Although Asara's nephew Asaaki rushed to the rescue from Edo Castle, he built Tamanawa Castle in Kamakura in October of the same year in order to repel this and further capture the Miura clan.

Gido often sends out his troops and engages in battle, but is gradually oppressed and confined to the Miura Peninsula. The Ogidani family also sent troops to help, but they were all repulsed.

In July 1516, Ogiya Tomoaki attacked Tamanawa Castle to rescue the Miura clan, but Sozui defeated him and attacked Misaki Castle, where Gido and Giui father and son were holed up. At the end of a fierce battle, Gido and Giui father and son died in the battle. The famous Miura clan perished, and the Ise clan subdued the entire Sagami area.

In 1518, he handed over the headship of the family to his eldest son, Ujitsuna, and died the following year, 1519. Two years later, his successor, Ujitsuna, founded Sounji Temple (Hakone Town, Kanagawa Prefecture) as a family temple.

Tamanawa Castle

It is said to have been built by Ise Moritoki in 1512, but it is also possible that there was a fort or small castle there even before that. The castle's outer moat was directly connected to the Kashio River, making it possible to take boats out to Sagami Bay, making it an important base for controlling naval forces and other forces. Furthermore, since it is close to Kamakura, it also serves as a defense for Kamakura.

After seizing Odawara Castle from the Omori clan and advancing into West Sagami, Moritoki fought against the Sagami Miura clan of East Sagami, but the battle turned into a long one, and at this time Tomoaki Uesugi, the head of the Ogidani Uesugi family in Musashi, who was the main force behind the Omori clan, holed up in Arai Castle. Tamanawa Castle was built in this area at the base of the Miura Peninsula, as it was necessary to prepare for a pincer attack as reinforcements from Yoshitaka Miura.

After the fall of the Miura clan, it also played a role as a protector of the Awa Satomi clan and as a protector of Odawara Castle. During the Hojo era, an important person from the family was appointed as the castle lord. The first lord of the castle, Ujitoki, was Moritoki's biological son, but he suddenly passed away in 1531.As a result, the second lord, Tamemasa, who was Ujitsuna's biological son, entered Tamanawa Castle, but was still a boy, and the Ogidani Uesugi family. His father, Ujitsuna, also oversees the reconstruction of Tsurugaoka Hachimangu Shrine, which was destroyed by fire during the battle with the Emperor and the attack by the Satomi clan, and his father, Ujitsuna, commutes between Odawara Castle and Tamanawa Castle to oversee government affairs.
Afterwards, Ujitsuna returned to Odawara Castle, but Tamemasa suddenly passed away in 1542. For this reason, Tsunari Hojo, Ujitsuna's son-in-law who had been assisting Tamemasa as castle lord for a long time, became the third lord of the castle under the pretext of being ``Tamemasa's adopted son.'' After that, the position of castle lord was inherited by four generations: Tsunari's son Ujishige, Ujishige's eldest son Ujishun, and his younger brother Ujikatsu.

Currently, a school is built on the site of the main enclosure of Tamanawa Castle, and the huge rock enshrined in front of the school gate is said to be part of the remains of Tamanawa Castle.