Editing Tokugawa Ieyasu (section)

==Ieyasu and Hideyoshi (1584–1598)==
=== Earthquakes and conflict with Hideyoshi===
{{see also|Battle of Komaki and Nagakute}}
[[File:Nagakute Historic Battlefield.jpg|thumb|Nagakute Historic Battlefield located in [[Aichi Prefecture]] ]]
As the Tokugawa clan's territory expanded, many of their regions were hit by earthquakes and heavy rains from 1583 to 1584. In particular, from May to July, heavy rains fell constantly from the Kantō region to the [[Tōkai region]], in what was dubbed the "heaviest flood in 50 years" in the historical record of ''Ietada-nikki''.<ref>{{cite book |title=家忠日記 / Ietada nikki |date=1968 |publisher=Rinsen Shoten |location=Kyōto |url=https://search.worldcat.org/title/ietada-nikki/oclc/20953775 |access-date=3 June 2024 |language=Ja |author=[[Matsudaira Ietada (Fukōzu)]]}}</ref> It was under these circumstances that the Tokugawa clan was forced to fight against the Hōjō clan and the Toyotomi government, because in 1584 Ieyasu had decided to support [[Oda Nobukatsu]], the eldest surviving son and heir of Oda Nobunaga, against [[Toyotomi Hideyoshi]]. The ''Ryumonji Kojiki'', written by successive chief priests at Ryumonji Temple in Tahara, Mikawa Province, records that in 1582 many people were mobilized in the Battle of Komaki and Nagakute, which led to the devastation of farmland and famine. 

The devastation of the Tokugawa clan's territory made it difficult to continue fighting against the Toyotomi government and they were forced to rebuild their country.<ref>{{Citation|author=Shiba Ryutaro |chapter=戦国大名徳川氏の徳政令|editor=Masaki Kubota  |title=松平家忠日記と戦国社会|publisher=Iwata Shoin |date=2011}}/Retitled:{{Citation|author=Shiba Ryutaro |chapter=徳川氏の領国支配と徳政令|title=戦国・織豊期大名徳川氏の領国支配|publisher=Iwata Shoin |date=2014}}</ref> This was a dangerous situation for the Tokugawa clan which could have resulted in their annihilation due to the Oda clan collapsing after Nobunaga's death.<ref name="The Maker of Modern Japan The Life of Tokugawa Ieyasu; Yasumasa proclamation">{{cite book |author1=Arthur Lindsay Sadler |author1-link=Arthur Lindsay Sadler |title=The Maker of Modern Japan The Life of Tokugawa Ieyasu |date=2014 |publisher=Taylor & Francis |isbn=9781136924705 |pages=123–124 |url=https://books.google.com/books?id=oftisLbVFwgC |access-date=9 May 2024 |language=En}}</ref>

Tokugawa troops took the traditional Oda stronghold of [[Owari Province|Owari]]. Hideyoshi responded by sending an army into Owari. Ieyasu decided to confront Hideyoshi's forces in [[Komaki]] because his general, Sakakibara Yasumasa, suggested the area was favorable for the Tokugawa force to fight incoming enemies from the west.<ref name="The Samurai A Military History; Komaki Nagakute">{{harvtxt|Stephen Turnbull |2013 |pp=162–163}}</ref> Additionally, Ieyasu and Nobukatsu formed an anti-Hideyoshi alliance with [[Chōsokabe Motochika]], through contact with [[Kōsokabe Chikayasu]].<ref>{{Cite book|author = Dai Yamamoto|year = 1988 |title = 長宗我部元親 |edition = 新装版 |publisher = 吉川弘文館 |isbn = 4642051031 |trans-title=Chosokabe Motochika  |page=103}}</ref>

[[File:Hoshizaki Castle 001.JPG|thumb|Stone memorial stele on the former site with brief description of the history of Hoshizaki castle (2009)]]
At first, Ieyasu ordered his generals [[Mizuno Tadashige]] and [[Mizuno Katsushige|Mizuno Katsunari]] to capture [[Hoshizaki Castle]].<ref name="Funahashi;NagakuteKatsunari">{{cite book |author1=Funahashi Takeshi | author2=Nagakute Katsunari |title=見た聞いた考えた豊臣秀吉大研究 地元にいるから秀吉が見えてきた! |date=1983 |publisher=ブックショップマイタウン |page=191 |url=https://ndlsearch.ndl.go.jp/books/R100000001-I23211009210126478 |access-date=20 May 2024 |language=Ja}}</ref> Then, as the Toyotomi army vanguard under the command of [[Toyotomi Hidetsugu]] started entering the area of Komaki, Ieyasu sent Yasumasa and Osuga Yasutaka in for a surprise attack and inflicted heavy losses on the Hidetsugu army before they were stopped by [[Hori Hidemasa]]. Hidemasa decided to retreat when Ieyasu brought his main forces forward.<ref>{{cite book |author1=Tetsuo Owada |author1-link=Tetsuo Owada |script-title=ja:豊臣秀次: 「殺生関白」の悲劇 |date=2002 |publisher=PHP 硏究所 |isbn=9784569621043 |url=https://books.google.com/books?id=Fn1xBAAAQBAJ |access-date=11 May 2024 |language=Ja}}</ref> 

Later, as another Toyotomi vanguard led by [[Mori Nagayoshi]] entered the area, Ieyasu had his senior generals, Sakai Tadatsugu, [[Okudaira Nobumasa]], and Matsudaira Ietada, beat Nagayoshi's troops, forcing him to retreat.<ref name="Toyotomi Hideyoshi; Stephen Turnbull, Komaki-Nagakute">{{cite book |author1=Stephen Turnbull |author1-link=Stephen Turnbull (historian) |title=Toyotomi Hideyoshi |date=2011 |publisher=Bloomsbury Publishing |isbn=9781846039614 |page=39 |url=https://books.google.com/books?id=HC61CwAAQBAJ |access-date=6 May 2024 |language=En}}</ref> In the last phase of this series of engagements, Nagayoshi returned with another Toyotomi general [[Ikeda Tsuneoki]]. However, both of them were repeatedly beaten on the field at Nagakute by Mizuno Katsunari,<ref name="Kusudo Yoshiaki 2009 14">{{harvtxt|Kusudo Yoshiaki |2009 |p=14}}</ref> and later, Ii Naomasa, caused the Toyotomi forces to suffer heavy losses with both Tsuneoki and Nagayoshi killed in action.<ref name="Japanese War History Volume 13: Komaki Role 1942 vers.">{{Cite journal|author=花見朔已|date=1942|title=小牧・長久手の役|journal=大日本戦史|publisher=三教書院|page=44}}</ref><ref name="Japanese War History Volume 13: Komaki Role">{{harvtxt|参謀本部 編 |1978|pp=35–39|}}</ref> 

Furious with the decimation of Nagayoshi's and Tsuneoki's forces, Hideyoshi mobilized his main army to crush Ieyasu's army in Nagakute. However, Ieyasu had already retreated before Hideyoshi's main forces arrived.{{sfn|Stephen Turnbull|2012|p=27}}<ref name="Mikawa Go Fudoki Seisetsu Daizen">{{cite book |title=Mikawa Go Fudoki Seisetsu Daizen Volume 42 & 43 |date=1853 |publisher=Aichi Prefectural Library |url=https://websv.aichi-pref-library.jp/wahon/detail/174.html |access-date=4 May 2024 |language=ja}}</ref>

After the Battle of Komaki and Nagakute in April, the front line in northern Owari reached a stalemate. At this time, Kanie Castle was located about three miles between Ieyasu's Kiyosu Castle and Nobuo's Nagashima Castle, and was connected to the Mie moat and three castles: Ono Castle, Shimojima Castle, and Maeda Castle. At that time, Kanie Castle was facing the sea and was one of the leading ports in Owari, along with Atsuta and Tsushima. Then on June 18, Ieyasu and Nobuo led 20,000 soldiers and besieged three castles: Kanie Castle, Maeda Castle, and Shimojima Castle.<ref name="Komaki Nagakute; Tatsuo">{{cite book |author1=Fujita Tatsuo |title=小牧・長久手の戦いの構造  |trans-title=Structure of the Battle of Komaki and Nagakute |date=2006 |publisher=岩田書院 |isbn=4-87294-422-4 |page=107 |url=http://www.iwata-shoin.co.jp/bookdata/ISBN4-87294-422-4.htm |access-date=14 May 2024 |language=Ja}}</ref> Kanie Castle was defended by [[Maeda Nagatane]] and [[Takigawa Kazumasu]]. Tadatsugu, Okanabe Mori, and Yamaguchi Shigemasa spearheaded the attack towards Shimojima castle, while Sakakibara Yasumasa, Osuga Yasutaka were deployed to capture any fleeing defenders.<ref>{{cite book |author1=神谷存心 |title=小牧陣始末記(日本戦史材料; 第1巻) |trans-title=The story of the end of the Komaki camp (Japanese military history materials; Volume 1) |date=1889 |publisher=武蔵吉彰 |location=Tokyo |url=https://ndlsearch.ndl.go.jp/books/R100000002-I000000431253 |access-date=14 May 2024 |language=Ja}}</ref><ref>{{cite book |author1=Kimura Takaatsu |editor1-last=Naotoki |editor1-first=Tamaru |title=武徳編年集成 |publisher=拙修斎 |url=https://www.digital.archives.go.jp/file/1217291.html |access-date=14 May 2024 |language=Ja}}</ref> 

During this siege, Ieyasu's [[hatamoto]] retainers, including Mizuno Katsunari, blockaded the port of the castle and hijacked two ships belonging to [[Kuki Yoshitaka]] to prevent any outside help for Kanie Castle.{{sfn|Hirai|1992|p=52}} After the fall of Shimojima castle on June 22, Oda Nobuo and Tokugawa Ieyasu launched an all-out attack on Kanie Castle. The soldiers led by Tadatsugu, who had been deployed at the main gate, were exhausted after days of fierce fighting, and in the evening, the soldiers of Yasumasa Sakakibara and Ietada Matsudaira entered Kaimonjiguchi in their place.<ref>{{cite book |author1=Narushima shichoku |author2=Udagawa Takehisa |author3=kuwata tadachika |title=改正三河後風土記 Volume 1 |trans-title=Revised Mikawa Go Fudoki Volume 1 |date=1976 |publisher=秋田書店 |page=197 |url=https://books.google.com/books?id=-IEzAQAAIAAJ |access-date=14 May 2024 |language=Ja}}</ref> On June 23, Ieyasu entered the castle with Sakakibara Yasumasa, subduing the castle.<ref name="Komaki Nagakute; Tatsuo" />

=== Becoming a vassal of the Toyotomi Regency ===
The conflict with Hideyoshi was long, and lasted until Nobukatsu decided to surrender to Hideyoshi. With this, Ieyasu lost his motivation to further oppose Hideyoshi and decided to also submit.<ref name=Sansom />{{sfn|Turnbull|1998|p=235}} After peace negotiations between Tokugawa Ieyasu and Toyotomi Hideyoshi in the aftermath of the [[Battle of Komaki and Nagakute]], Naomasa, Tadakatsu, and Yasumasa gained fame in Kyoto. The following month, the three of them were joined by Tadatsugu Sakai while accompanying Ieyasu on a trip to Kyoto, where the four of them became famous.<ref name="徳川四天王">{{cite book |author1=Tetsuo Nakamura |author2=Kazuo Murayama |title=徳川四天王: 精強家康軍団奮闘譜 歴史群像シリーズ22号 |date=1991 |publisher=学研プラス |isbn=4051053679 |pages=111, 125 }}</ref>

However, on November 13, 1585, [[Ishikawa Kazumasa]] defected from Ieyasu to Hideyoshi.{{sfn|Tanaka|2007|p=14}} Ogasawara Sadayoshi, who also defected and followed Kazumasa, led over 3,000 troops to attack Takato. In Takato Castle there were only 40 cavalrymen and 360 soldiers other than the elderly Hoshina Masatoshi, but Masatoshi himself took command and defeated the Ogasawara forces in open battle. This prevented the collapse of Tokugawa rule in Shinano and Ieyasu awarded Masanao with the sword of Tsunehisa on December 24 in recognition of his military achievements.{{sfn|Hirayama|2011|p=179-182}} 

These incidents caused Ieyasu to undertake massive reforms of the Tokugawa clan governmental structure by incorporating more Takeda clan vassals into his administrations, both civil and military. At first, Ieyasu ordered Torii Mototada, who served as the county magistrate of Kai, to collect military laws, weapons, and military equipment from the time of Takeda Shingen and bring them to Hamamatsu Castle in Hamamatsu City, Shizuoka Prefecture. Later, he appointed two former Takeda vassals, Naruse Masakazu and Okabe Masatsuna, as magistrates under authority of Ii Naomasa and Honda Tadakatsu. He ordered all former Takeda vassals who served him to impart any military doctrines and structures they knew from their service to the Takeda clan.,<ref name="Shogun and Samurai Tales of Nobunaga, Hideyoshi, and Ieyasu">{{cite book |author1=Okanoya Shigezane |translator=Andrew and Yoshiko Dykstra |title=Shogun and Samurai Tales of Nobunaga, Hideyoshi, and Ieyasu |date=2007 |publisher=University of Hawaiʻi; Japanese Literature Translations by Yoshiko K. Dykstra |location=Mānoa |page=147 |url=https://scholarspace.manoa.hawaii.edu/server/api/core/bitstreams/0d434090-1065-4bc9-ab1f-31611d094ba2/content |access-date=2 June 2024 |language=En}}</ref> He ordered three of his prime generals, Ii Naomasa, Honda Tadakatsu, and Sakakibara Yasumasa, to serve as the supreme commanders of these new military regiments.<ref>{{cite web |author1=Watanabe Daimon |title=家臣が出奔するというピンチをチャンスに変えた、徳川家康の先見性とは |publisher=渡邊大門 無断転載を禁じます。 © LY Corporation |website=yahoo.co.jp/expert/articles/ |url=https://news.yahoo.co.jp/expert/articles/a826d1080466b78200a81bb25683c64862298924 |access-date=2 June 2024 |language=Ja}}</ref> The same year, Hideyoshi forced his younger sister [[Asahi no kata]] to divorce her husband, who then committed suicide, and sent her to Ieyasu with the offer of marrying her.{{Sfn|Fujino |1990|p=59}}

In 1586, in response to Ishikawa Kazumasa's defection from the Tokugawa clan, former Takeda clan vassals from Kai and Shinano province, including Yonekura Tadatsugu, sought to reaffirm their loyalty to Ieyasu by presenting their family members as hostages.<ref>{{harvtxt|Kazuhiro Marushima (丸島和洋)|2015|p=706}}</ref>

Later the same year, Hideyoshi sent [[Ōmandokoro|his own mother]] as a hostage to Ieyasu. If Ieyasu continued to refuse to go to Kyoto after such a gesture, it would give Hideyoshi a just cause for war. Ieyasu finally decided to become Hideyoshi's vassal.<ref>{{cite web|url=https://hamamatsu-daisuki.net/ieyasu/person/relation/|title=1586年に秀吉の母・大政所を人質として岡崎に迎えた後に上洛。大坂城で秀吉に臣下の礼をとり、秀吉の家来となりました。|publisher=Hamamatsu & Lake Hamana Tourism Bureau|access-date=June 7, 2024}}</ref>

=== Ruling Kantō and suppressing rebellions ===
{{see also|Siege of Odawara (1590)|Edo}}
[[File:Odawara-jo.jpg|thumb|250px|right|Odawara castle in 2024]]

In 1590 May, Ieyasu participated in the [[Siege of Odawara (1590)|campaign against the Hōjō clan]]. Odawara, which was the last Hōjō clan stronghold, saw almost no significant military action, with the exception of Ii Naomasa's night raid attack. This happened after a group of miners from [[Kai Province]] dug under the castle walls, allowing troops under Naomasa to enter and engage the enemy.{{sfn|Turnbull|1998|p=241}} After the surrender of the Hōjō clan, Ieyasu sent Naomasa and Sakakibara Yasumasa with 1,500 soldiers to witness the seppuku of the defeated enemy generals, [[Hōjō Ujimasa]] and [[Hōjō Ujiteru]].<ref>{{cite book |author1=kuwata tadachika |author2=yamaoka sōhachi |author3=Army. General Staff Headquarters |title=日本の戦史 Volume 4 |date=1965 |publisher=德間書店, 昭和 40–41 [1965–66] |location=Japan |page=263 |url=https://books.google.com/books?id=yAkmAAAAMAAJ |access-date=16 May 2024 |language=Ja}}</ref> As result of his distinguished service during the campaign, Naomasa was awarded with an increase in his domain to 120,000 koku.<ref name="高崎市史 Volume 1; Naomasa Odawara">{{cite book |author1=高崎市史編さん委員会 |title=高崎市史 Volume 1 |date=1968 |publisher=高崎市 |page=151 |url=https://books.google.com/books?id=hdwNAAAAMAAJ |access-date=9 May 2024 |language=Ja}}</ref> Daidōji Masashige, a senior Hōjō clan retainer, was also forced to commit seppuku by Hideyoshi, however, his children were spared from execution at the behest of Ieyasu. The eldest son, Daidōji Naoshige, became Ieyasu's vassal after the death of Ujinao.<ref>{{cite web |author1=とーじん さん |title=「大道寺政繁」北条氏の重臣として内政・軍事両面で活躍も、最期は処刑された悲運の将 |trans-title="Daidouji Masashige" was a senior retainer of the Hōjō clan, and played an active role in both domestic and military affairs, but was executed in the end |url=https://sengoku-his.com/352 |website=戦国ヒストリー |publisher=sengoku-his.com |access-date=11 June 2024 |language=Ja |date=2019 |quote=Haruhisa Shimoyama, (後北条氏家臣団人名事典 / Biographical Dictionary of the Later Hojo Clan's Vassals) Tokyodo Publishing, 2006; Kuroda Motoki, (北条氏康の家臣団：戦国「関東王国」 / Hojo Ujiyasu's Vassals: The Family and Elders Who Supported the Kanto Kingdom in the Warring States Period) Yosensha, 2018; Kuroda Motoki, (戦国北条家一族事典 / Encyclopedia of the Hojo Clan in the Warring States Period), Ebisu Kosho Publishing, 2018.}}</ref>

On October 28 of the same year, a {{Ill|Waga-Hienuki Rebellion|lt=massive revolt|jp|和賀・稗貫一揆}} against the Toyotomi government in [[Mutsu Province]] was incited by Hienuki Hirotada and Waga Yoshitada. In response, Hideyoshi sent a punitive expedition with an army 30,000 strong led by Ieyasu Tokugawa, [[Toyotomi Hidetsugu]], [[Date Masamune]], [[Ishida Mitsunari]], [[Ōtani Yoshitsugu]], [[Gamō Ujisato]], [[Uesugi Kagekatsu]], [[Satake Yoshishige]], and [[Maeda Toshiie]] in order to pacify the rebellion.<ref name="Aomori Wagahienuki">{{cite book |author1=青森県 |title=青森県史: 資料編. 中世, Volume 1 |trans-title=Aomori Prefectural History: Documents. Middle Ages, Volume 1 |date=2004 |publisher=Aomori Prefecture History Editor Medieval Section|pages=274, 702 |url=https://www2.i-repository.net/contents/kenshi-front/ |access-date=19 May 2024 |language=Ja}}</ref>

In 1591, Ieyasu gave up control of his five provinces ([[Mikawa Province|Mikawa]], [[Tōtōmi Province|Tōtōmi]], [[Suruga Province|Suruga]], [[Shinano Province|Shinano]], and [[Kai Province|Kai]]) and moved all his soldiers and vassals to his eight new provinces in the Kantō region. The proclamation of this decision happened on the same day as Hideyoshi entered Odawara castle after the Hōjō clan formally surrendered.<ref name="Ando Yuichiro; Tokugawa Kanto" /> The moment Ieyasu was appointed to rule Kantō, he immediately assigned his premier vassals, including Ii Naomasa, Honda Tadakatsu, Sakakibara Yasumasa, and Sakai Ietsugu, the son of Sakai Tadatsugu, to each control a large area of the former Hōjō clan territories in Kantō. Historians saw this step as aimed at bringing order to the newly subdued population of the area, while also guarding the eastern domains from any influence or threat from the [[Satomi clan]], which had not yet submitted to Toyotomi rule at that time.<ref>{{cite journal |author1=Yuu Kawamura |title=徳川家康の新領国に対する家臣団配置―小田原落城直後の上総の一動向― |journal=『歴史手帳』6巻2号）(History Notebook, Vol. 6, No. 2)|trans-title=Deployment of Tokugawa Ieyasu's vassals in his new territory: Movements in Kazusa immediately after the fall of Odawara Castle  |language=Ja}}</ref><ref>{{cite book |author1=Otaki Town History Editorial Committee |title=大多喜町史 |trans-title=Otaki Town History |date=1991 |location=Otaki, Chiba Prefecture |pages=310–311 |url=https://ndlsearch.ndl.go.jp/books/R100000002-I000002127280 |access-date=22 May 2024}}</ref> Meanwhile, Ieyasu himself established his personal seat of power in Edo town, which at that time was an underdeveloped town in Kantō.{{sfn|Nakamura|2010|p=210}}

[[File:Kanto Region in Japan.svg|thumb|Kanto Region in Japan]]
Historian Adam Sadler saw this step as the riskiest Ieyasu ever made—to leave his home province and rely on the uncertain loyalty of the former Hōjō clan samurai in Kantō. In the end, it worked out brilliantly for Ieyasu. He reformed the Kantō region, controlled and pacified the Hōjō samurai, and improved the underlying economic infrastructure. Also, because Kantō was somewhat isolated from the rest of [[Japan]], Ieyasu was able to ally with daimyo of north-eastern Japan including [[Date Masamune]], [[Mogami Yoshiaki]], [[Satake Yoshishige]] and [[Nanbu Nobunao]]; he was also able to maintain a unique level of autonomy from [[Toyotomi Hideyoshi]]'s rule. Within a few years, Ieyasu had become the second most powerful daimyo in Japan. An anecdotal proverb says, "Ieyasu won the Empire by retreating."<ref>[[#Adam|Sadler]], p. 164.</ref> 

Modern Japanese historians reject that this was a deliberate move by Ieyasu since it was an order from Hideyoshi.<ref name="Ando Yuichiro; Tokugawa Kanto" /> Nevertheless, [[:jp:渡邊大門|Watanabe Daimon]] stated that, while the general opinion was that Ieyasu was reluctant about his transfer to Kantō, this perception was unfounded. Instead, Daimon suspected that Ieyasu actually responded to this transfer positively as he saw potential in making undeveloped Edo into his seat of power.<ref>{{cite web |title=徳川家康は泣く泣く江戸に行ったのではなく、実は前向きだった |url=https://news.yahoo.co.jp/expert/articles/af0ad7e21140c617714675385d17bea40f7b2f45 |website=yahoo.co.jp/expert |publisher=渡邊大門 無断転載を禁じます。 © LY Corporation |access-date=2 June 2024 |author=Watanabe Daimon|language=Ja |date=2023}}</ref>{{efn|Historian [[:jp:安藤優一郎|Andō Yūichirō]] added, the true intention of Hideyoshi in transferring Ieyasu to Kantō was to weaken the power of the Tokugawa clan by moving them from their ancestral land in Mikawa, as he expected the former Hōjō vassals in Kantō would rebel against Ieyasu.<ref name="Ando Yuichiro; Tokugawa Kanto" /> However, Kahara Toshi stated recent academic consensus is that this step by Hideyoshi would better viewed as a sign of his trust in Ieyasu's capability to rebuild the post-war Kantō.<ref name="Kahara Toshi; Tokugawa Kanto">{{cite web |author1=Kahara Toshi |title=｢家康へのいやがらせ｣ではなかった…最新研究でわかった｢秀吉が家康を関東に追いやった本当の理由｣  |trans-title=It wasn't "harassment for Ieyasu"...Recent research reveals "the real reason Hideyoshi drove Ieyasu to Kanto |url=https://president.jp/articles/-/74422?page=1 |website=President Online |access-date=4 June 2024 |pages=1–4 |language=Ja |date=2022}}</ref>}} 

Similarly, Andō Yūichirō viewed this transfer as an advantage for the Tokugawa regime in the long run, as this move was not only doubled the territory that he controlled, but it further added numerous new vassals in Kantō to the already impressive political and military power of the Tokugawa regime, which had already absorbed the armies of the Imagawa and Takeda clans before. Yūichirō added that aside from the samurai from Imagawa, Takeda, and Hōjō, the Mikawa samurai clans who were traditional followers of the Tokugawa clan also lost their sense of independence after being transferred into a new unfamiliar territory, which increased their sense of dependence on Ieyasu, in effect further minimizing the possibility of them going renegade and betraying Ieyasu, as Ishikawa Kazumasa had done several years earlier.<ref name="Ando Yuichiro; Tokugawa Kanto">{{cite web |author1=Andō yūichirō |title=だから織田と豊臣はあっさり潰れた…徳川家康が｢戦国最後の天下人｣になれた本当の理由 |trans-title=The reason why Oda and Toyotomi were easily defeated... Tokugawa Ieyasu was the "last of the Sengoku period." |url=https://president.jp/articles/-/64535?page=1 |website=President Online |access-date=4 June 2024 |pages=1–4 |language=Ja |date=2022}}</ref>

After the Waga-Hienuki rebellion, the [[Kunohe rebellion]] led by Kunohe Masazane broke out on March 13, 1591. This caused the punitive expedition army to split their forces as Ieyasu, Naomasa, Ujisato, and some commanders changed their focus to suppress Masazane's rebellion first.<ref name="Hideyoshi rebellion; Seiji Kobayashi">{{harvtxt|Seiji Kobayashi |1994 |p=189}}</ref><ref>{{cite book |author1=Iwate Prefectural Educational Research Institute |title=岩手県史  |trans-title=Iwate Prefecture History |date=1966 |publisher=杜陵印刷 |page=105 |url=https://ndlsearch.ndl.go.jp/en/books/R100000002-I000001190277 |access-date=15 May 2024 |language=Ja}}</ref> Ieyasu, who at that time was also busy suppressing rebellions with his main commanders, including Sakakibara Yasumasa, Ii Naomasa, and Honda Tadakatsu, arrived at Iwatesawa, Tamazukuri district, Mutsu (modern day [[Iwadeyama, Miyagi|Iwadeyama]], [[Miyagi Prefecture]]) on August 18, where he camped until October and led the troops.<ref name="所沢市史, Volume 10; Kunohe rebellion & Kanto">{{cite book |author1=所沢市史編さん委員会 |title=所沢市史, Volume 10 |date=1979 |publisher=所沢市 |page=466 |url=https://books.google.com/books?id=3gE0AQAAIAAJ |access-date=30 May 2024 |language=Ja}}</ref> 

During the operation against the Kunohe clan rebels, Naomasa Ii became the vanguard with [[Nanbu Nobunao]]. As they advanced towards Kunohe castle, they faced a small force of Kunohe rebels which they easily defeated.<ref name="Hideyoshi rebellion; Seiji Kobayashi" /> Naomasa suggested to besiege the castle until they surrendered, which was met with agreement.<ref>{{cite book |author1=Ishidoriya Town History Compilation Committee |title=石鳥谷町史 上-下卷 [1-2] · Volume 1 |date=1979 |publisher=石鳥谷町 |page=299 |url=https://books.google.com/books?id=dBs5AAAAMAAJ |access-date=15 May 2024}}</ref> 

On 4 September, the rebels executed the prisoners inside the castle and incited mass suicide after setting fire to the castle. The castle burned for three days and nights killing all within.<ref name="Turnbull;Kunohe">{{cite book|last=Turnbull|first=Stephen|title=Hatamoto: Samurai Horse and Foot Guards 1540-1724|year=2010|publisher=Osprey|language=English|isbn=9781846034787}}</ref><ref name="Hideyoshi rebellion; Seiji Kobayashi" /><ref name="Aomori Wagahienuki" /> The rebellions were suppressed by June 20, with Waga Yoshitada being slain in battle,<ref>{{cite book |author1=中央公論新社(編) |title=歴史と人物 Volume 11 |trans-title=History and People volume 11 Interesting People Japanese History Ancient and Medieval Edition |date=2020 |publisher=中央公論新社(編) |isbn=9784128001453 |page=104 |url=https://books.rakuten.co.jp/rb/17253284/ |access-date=19 May 2024 |language=Ja}}</ref> while Hienuki Hirotada was sentenced to "''[[:jp:改易|Kaieki law]]''" which stated that his and his clan's status and rights as samurai were stripped.<ref>{{Cite book|author=Hosoi Kei |title=南部と奥州道中 |trans-title=Nanbu and Oshu Road |url=https://www.yoshikawa-k.co.jp/book/b33887.htm|publisher=Yoshikawa Kobunkan|date=2002|page=104 |isbn=4642062068}}</ref> 

As the operation ended, Ieyasu returned to Edo on October 29 and began managing his new territory in the Kantō region.<ref name="所沢市史, Volume 10; Kunohe rebellion & Kanto" /> Ieyasu managed to establish his home base in Kantō, and built sustainable economic infrastructure in the region.{{sfn|Nishimoto|2010|p=141}} Ieyasu also employed [[:jp:後藤庄三郎|Gotō Shōzaburō]], head of the gold mining and metal industries of the Sengoku period, to mint gold coins and establish a bank-like institution for the Tokugawa clan's government.<ref name="Hamada Kōichirō  Ieyasu vassals">{{cite web |author1=Takayuki Emiya (江宮隆之) |author2=Rekishijin Editorial Department |title=徳川幕府の日本銀行・金座の当主であった造幣ブレーン「後藤庄三郎」とは？ |trans-title=Who was Goto Shozaburo, the minting brain behind the Tokugawa Shogunate's Bank of Japan and Gold Mint? |url=https://www.rekishijin.com/28213 |website=Rekishijin |publisher=ABC ARC, inc. |access-date=24 June 2024 |language=Ja |date=2023 |quote=From "The Truth About Tokugawa Ieyasu" in the February 2023 issue of Rekishijin article}}</ref>

In 1592, Toyotomi Hideyoshi [[Japanese invasions of Korea (1592–98)|invaded Korea]] as a prelude to his plan to attack [[China]]. The Tokugawa clan samurai didn't take part in this campaign, as Hideyoshi had ordered the  eastern provinces' daimyo including Ieyasu, Uesugi Kagekatsu, and Date Masamune to maintain logistical support for the war effort in [[Nagoya Castle]].{{efn|Historian Kōichirō Hamada examined the historical records regarding the Korean invasion where Ieyasu expressed his eagerness to participate in this campaign. However, Hideyoshi organized to prioritize the daimyo lords from western provinces as vanguard which divided into 9 divisions, as he saw their positions were closer to Korea. Hamada stated by the fact that Korean invasion were dragged for years, there is good possibility that Ieyasu and other eastern province daimyo lords would be sent to Korea if Hideyoshi lived longer and the Korean campaign continues.<ref name="Ieyasu Korea; Kōichirō Hamada">{{cite web |author1=Kōichirō Hamada (田 航一郎) |title=暴走する秀吉を誰も止められなかった…名だたる武将が出兵する中､なぜ家康は朝鮮出兵を回避できたのか |url=https://president.jp/articles/-/74100?page=1 |website=president.jp |access-date=4 June 2024 |pages=1–4 |language=Ja |date=2023}}</ref>}}

In 1593, Toyotomi Hideyoshi fathered a son and heir, [[Toyotomi Hideyori]]. Later, though still in early 1593, Ieyasu himself was summoned to Hideyoshi's court in [[Nagoya Castle (Hizen Province)|Nagoya]] (in [[Kyushu]], not the similarly spelled city in [[Owari Province]]) as a military advisor and was given command of troops meant as reserves for the Korean campaign. Ieyasu stayed in Nagoya intermittedly for the next five years.<ref name="Sansom 1961">{{cite book |url=https://books.google.com/books?id=0syC6L77dpAC&pg=PA353 |title=A History of Japan, 1334–1615 |first= Sir George Bailey |last=Sansom |publisher= Stanford University Press |year= 1961 |isbn= 0-8047-0525-9 |page=353}}</ref>

In July 1595, the "[[Toyotomi Hidetsugu]] Incident" occurred. In response to this major incident shaking the Toyotomi government, Hideyoshi ordered various daimyo to come to Kyoto in an attempt to calm the situation. Ieyasu also came to Kyoto on Hideyoshi's orders. From this point on, Ieyasu spent longer and longer periods in Fushimi Castle than in his underdeveloped residence, Edo Castle. Due to this chain of events, Ieyasu's position in the Toyotomi government had risen, but by being at the center of the government, Ieyasu was able to learn directly about the central government's political system.<ref name="owada2007">{{Cite book |author=Tetsuo Owada |trans-title=Tokugawa Ieyasu, the Great Leader of Sunpu  |author-link=Tetsuo Owada |year= 2007 |title= 駿府の大御所 徳川家康 |publisher= 静岡新聞社 |series= 静新新書}}</ref>