In the third year of Yonglu, there was a battle in a narrow bucket. Imagawa Yoshimoto, who commanded 5, troops from Sanhe, Yuanjiang and Suruga, went to Los Angeles and died in a narrow barrel. Matsuhei Yuankang, who had scored in Dacheng, took the opportunity to return to Sanhe, the old country, based in Okazaki City, and became independent from today's Sichuan family and made an alliance with Nobutaka, and changed his name to Tokugawa Ieyasu. After Jia Kang became self-reliant, in the sixth year of Yu Yonglu, the Three Rivers rebelled against a slap in the face, and Okubo's loyal family gathered to fight with a slap in the face and made great achievements. After that, the loyal family acted as an intermediary to actively mediate the dissatisfaction of one slap. In May of the third year, Takeda Katsura invaded and surrounded Changshinohara City. At the request of Jiakang, Nobunobu Oda personally went out to help. Tadashi Okubo and his brother Tadashi served as pioneers of the Tokugawa Army and led the foreign gun troops to shoot in three stages, which greatly defeated the left-wing Yamagata Masakage 3, red cavalry of Takeda Army. Okubo Tokugawa was very active in this battle. Even Nobuka, who was far away in the mountain, asked Jiakang, "The symbol of Tokugawa potential is Jin Yangyu Butterfly. Cake. ",Jia Kang replied," It's the Okubo brothers! Brother Butterfly (the symbol of loyalty to the world) and Brother Bing (the symbol of loyalty to Zuo) are all my ministers.

The Takeda family, the former nemesis of Chang Hsiao-hui after the war, was badly weakened. Naturally, Tokugawa Ieyasu would not miss this good opportunity and immediately launched a comprehensive counterattack to recover the lost land one by one. In June of the third year of Tianzheng, Tadashi Okubo made great contributions as the main force in the Raiders of Ercuo City, and became the Lord of Ercuo City after the war.

Ten years ago, the change of Benneng Temple took place, and Nobuya Nobuya died suddenly. The two countries, namely Jiafei Nobuya, which were newly occupied by Odaya Army, immediately became turbulent. Tokugawa Ieyasu waited for an opportunity to incite the rebellion of the people of Odaya, and Kawajiri Hidetaka, the general of Odaya, was killed by the rebels. When Mori Nagayoshi saw that the situation was difficult, he led the army to withdraw, and the two places were occupied by Tokugawa Ieyasu.

After Tokugawa Ieyasu pacified Nobu, one of its counties, Zuojiu, was given to Nobu Tadashi, who was appointed as Nobu. At the beginning of Nobu's takeover, Nobu Tajo and Sanada Masayuki, who owned Numata City, had problems in territory distribution. Fortunately, Lai Tadashi was clever and fair, and the three parties reached an agreement without incident.

However, the territorial dispute didn't end in the 11th year of Tianzheng. Jiakang and Kitajima Naoki reached an agreement on dividing up Takeda's old collar: 1. Shangzhou was divided by Kitajima's family, and A letter was collected by Tokugawa's family; 2. Ueno Numata was collected by Kitajima's family, and both Jiaju's Jiazhou and Sakuma's Xinzhou were ceded to Tokugawa's family; 3. Jiakang's daughter Duji was married to Kitajima Naoki. This treaty was very unfavorable to Sanada Masayuki, who occupied Numata City, so Chang Xing complained to Jia Kang, but Jia Kang only responded with a perfunctory attitude. Chang Xing saw through Jia Kang's decision to sacrifice his intention, so Sanada Masayuki moved to Ueda City to reorganize his armaments to ensure the success of the defense.

in the spring of the following year, after Tokugawa Ieyasu won a partial victory in the first world war with Komatsu and Takashi of Toyotomi Hideyoshi, he invited Kitajima to attack Sanada Masayuki on a large scale at the same time. Kitajima was the general of Kitajima's family, and led 7,5 troops to attack Marsha City. Tokugawa's family sent 8, generals, such as Tadashi Okubo and Akihito Hirayama, to lead an attack on Yazawa City with 2, troops. Unexpectedly, the commander of Marsha City was the first. Four hundred soldiers were sent out to attack Jia Kang in front of the battle line, which caused great anger of the Tokugawa Army, which is famous for its loyalty and straightness. Tian Jun fought and left, and Chang Xing took the opportunity to lead two thousand soldiers to attack from the back of the Tokugawa Army. Okubo, the commander of the Ren Dechuan Army, suffered many battles. As soon as he saw the scolding of the real Tian Jun, he had already anticipated this skill, so he left three thousand troops of this battle line early to resist Chang Xing's onslaught.

Unexpectedly, at this time, Sanada Yukimura, the second son of Chang Xing, unexpectedly launched a wild attack with only 2 cavalry, and Pingyan, the deputy commander, was close to Ji Jun's army. Later, Shinji, the eldest son of Chang Xing, led 1, ambushes from the north, and Yasuzawa Shiro from the northeast led 5 troops out of Ueda to join the siege. Therefore, Okubo had to retreat to Qianqu River. Unexpectedly, due to the heavy rain on the eve of the gorge, the loyal person who fell into the trap of Sanada Masayuki was killed by the real Tian Jun who was pursued (However, according to historical records, the first time in Ueda's wartime, Shinji Shinfan, that is, Sanada Yukimura was not in Ueno, but stayed as a hostage in the spring mountain city. What's the history? It's not clear whether Xingcun participated in the first Battle of Ueda. )

In the seventeenth year of the reign of Emperor Toyotomi Hideyoshi, after pacifying the Kyushu Island in Shikoku, he asked the Xiongnu to surrender to the Kitajima family in the Five Dynasties of Kanto. However, in the end, because of the territory of the Kitajima family, the Kitajima family attacked the famous Hutaocheng led by Sanada Masayuki, and Hideyoshi launched a crusade against Odahara in a rage. At that time, Okubo was tied with Benduo Zhongsheng and Inoue Zhizhi as pioneers and made meritorious deeds.

after the war, Tokugawa Ieyasu was transferred to Eight Kanto States, and Tokugawa Ieyasu, which entered the Kanto Plain, took Edo City as its residence city, and gave Tadashi Odawara City, the old Kitajima family residence city located in Kanto-Kansai, to Zhongshi, and took 45, stone territory. Became a vassal of Odawara. Shortly after entering the city, Tadashi Okubo died of illness in September of the third year of Wenlu, and he was given the name "Genyuan Rituo Daju".