Siege of Osaka explained

Conflict:Siege of Osaka
Partof:the late Sengoku Period and the early Edo period
Date:November 8, 1614 – January 22, 1615 and May – June 1615
Place:Osaka Castle, Osaka, Japan and surrounding areas
Map Type:Japan Osaka Prefecture#Japan
Map Relief:1
Casus:Toyotomi Hideyori prepares for an uprising against the new Tokugawa shogunate.
Result:Tokugawa shogunate victory; all threats to the shogunate temporarily eliminated.
Combatant1:Tokugawa shogunate and its loyalist banners:
Combatant2:Toyotomi clan and its loyalist banners:
Commander1:Tokugawa Ieyasu
Tokugawa Hidetada
Todo Takatora
Ii Naotaka
Matsudaira Tadanao
Date Masamune
Honda Masanobu
Honda Tadatomo
Satake Yoshinobu
Asano Nagaakira
Maeda Toshitsune
Uesugi Kagekatsu
Mōri Hidenari
Sanada Nobuyuki
Hosokawa Tadaoki
Mizuno Katsushige
Tachibana Muneshige
Commander2:Toyotomi Hideyori
Yodo-dono
Sanada Yukimura
Gotō Mototsugu
Tsutsui Sadatsugu
Akashi Takenori
Chōsokabe Morichika
Mōri Katsunaga
Fukushima Takaharu
Kimura Shigenari
Ōno Harunaga
Sanada Daisuke
Ban Naoyuki
Oda Nobukatsu (defected to Tokugawa side)
Hosokawa Okiaki
Strength1:164,000 (winter)
150,000 (summer)
Strength2:120,000 (winter)
60,000 (summer)

The was a series of battles undertaken by the Japanese Tokugawa shogunate against the Toyotomi clan, and ending in that clan's destruction. Divided into two stages, the winter campaign and the summer campaign, it lasted from 1614 to 1615. The siege put an end to the last major armed opposition to the establishment of the Tokugawa shogunate. The end of the conflict is sometimes called the, because the era name was changed from Keichō to Genna immediately following the siege.

Background

See main article: Battle of Sekigahara and Azuchi–Momoyama period.

When Toyotomi Hideyoshi died in 1598, Japan came to be governed by the Council of Five Elders, among whom Tokugawa Ieyasu possessed the most authority. After defeating Ishida Mitsunari in the Battle of Sekigahara in 1600, Ieyasu essentially seized control of Japan for himself and abolished the council. In 1603, the Tokugawa shogunate was established with its capital at Edo. Hideyoshi's son Toyotomi Hideyori and his mother Yodo-dono were allowed to stay at Osaka Castle, a fortress that had served as Hideyoshi's residence. Hideyori remained confined to the castle for several years. In addition, as a mechanism of control, it was agreed that in the year 1603 he would marry the daughter of Tokugawa Hidetada, Senhime, who was related to both clans. Ieyasu sought to establish a powerful and stable regime under the rule of his own clan. Only the Toyotomi clan, led by Hideyori under the influence of Yodo-dono, remained an obstacle to that goal.

In 1611, Hideyori finally left Osaka, meeting with Ieyasu for two hours at Nijō Castle. Ieyasu was surprised by Hideyori's behavior, contrary to popular belief that the boy was just "useless". This belief had been spread by Katagiri Katsumoto, Hideyori's personal guardian assigned by Ieyasu since 1599, and who had the intention of dissuading any aggression against the heir. In 1614, the Toyotomi clan rebuilt Osaka Castle. At the same time, the head of the clan sponsored the rebuilding of Hōkō-ji(Great Buddha of Kyoto) in Kyoto. These temple renovations included the casting of a great bronze bell, with inscriptions that read "May the state be peaceful and prosperous" (国家安康 kokka ankō), and "May noble lord and servants be rich and cheerful" (君臣豊楽 kunshin hōraku). The shogunate interpreted "kokka ankō" (国家安康) as shattering Ieyasu's name (家康) to curse him, and also interpreted "kunshin hōraku" (君臣豊楽) to mean "Toyotomi's force (豊臣) will rise again," which meant treachery against the shogunate. Tensions began to grow between the Tokugawa and the Toyotomi clans and only increased when Toyotomi began to gather a force of rōnin and enemies of the shogunate in Osaka. Ieyasu, despite having passed the title of shōgun to his son in 1605, nevertheless maintained significant influence.

After the Hoko-ji Temple Bell Incident, Yodo-dono sent Lady Okurakyo, Lady Aeba and Katagiri Katsumoto to Sunpu to see Tokugawa Ieyasu. In this meeting, Ieyasu hatched a plot to induce a split among the people of the Toyotomi family. On one hand, Ieyasu proposed a generous demand towards Lady Okurakyo. On the other hand, Ieyasu made severe demands on Katagiri Katsumoto, who represented the moderates and had been separately asking Ieyasu to save the Toyotomi family.

Despite Katagiri Katsumoto's attempts to mediate the situation, Ieyasu found the ideal pretext to take a belligerent attitude against Yodo-dono and Hideyori. The situation worsened in September of that year, when the news reached Edo that in Osaka they were grouping a large quantity of rōnin at the invitation of Hideyori. Katsumoto proposed that Yodo-dono be sent to Edo as a hostage with the desire to avoid hostilities, which she flatly refused. Suspecting him of trying to betray the Toyotomi clan, Yodo-dono banished Katsumoto and several other servants accused of treason from Osaka castle, sending them to the service of the Tokugawa clan. Consequently, any possibility of reaching an agreement with the shogunate was dissolved. This last incident led to the beginning of the siege of Osaka.

Preparations

As preparations, Hideyori sent many letters to most daimyo lords in Japan who he predicted would sympathize with the Toyotomi clan. However, his efforts were largely fruitless as his letters which delivered by his couriers were rejected by many of the applicants. Hachisuka Iemasa at first were hesitant, until his son convinced him to not accept Hideyori invitation to rebels against the Shogunate. meanwhile, Shimazu Tadatsune straightly reject his invitation as Tadatsune stated the Shimazu clan still recovering from the Sekigahara war and has no intention to stand up against Ieyasu. Tadatsune also returned a sword gift from Hideyori. An envoy of Toyotomi clan dispatched to convince Ikeda Tadakatsu, lord of Sumoto in Awaji Island and son of Ikeda Terumasa, also failed, as The Ikeda clan instead arrested the envoys.[1] Furthermore, The Toyotomi clan also failed to convince the Mōri clan under the lead of Mōri Terumoto to join their side. Terumoto instead rather supporting the Tokugawa shogunate, as on November 3, Terumoto ordered his vassals Mōri Motochikazu and Motoyuki Sugimori, who were in charge of Mori Hidemoto's absence, to send half of the troops east if Hidemoto asked them to march out to aid the shogunate fought the Toyotomi, while the remaining half, including Sugimori, Motoyoshi Nishi, and Shichirobei Misawa, were to stay in Chofu as caretakers, and to retreat to Hagi if something happened that would make it impossible to maintain Chofu.

Meanwhile, the shogunate also prepared their war efforts by stockpiling their ammunitions. in May, there is a company of British merchants tried to sell lead in Hirado. However, they failed to find any buyer. but their existence were reported William Adams to the shogunate, who end up bought all leads those merchants sell. Furthermore, in the same month there are also other merchant company from Dutch which also selling lead, and ends up being bought by the Shogunate either. Later in June, Tokugawa Ieyasu purchased a large amount of cannons, gunpowder, and bullets from British merchants, where Adams acted as the middleman, and the prices were 1 kan for cannons, 2.3 bun for gunpowder, and 1.6 bun for bullets.[2]

Winter campaign

In November of 1614, Tokugawa Ieyasu decided not to let this force grow any larger, and led 164,000 men to Osaka. The count does not include the troops of Shimazu Tadatsune, an ally of the Toyotomi cause who nevertheless did not send troops to Osaka. The siege began on 19 November, when Ieyasu led 3,000 men across the Kizu River, destroying the fort there. A week later, he attacked the village of Imafuku with 1,500 men, against a defending force of 600. With the aid of a squad wielding arquebuses (a weapon widely used by Japanese forces at this time), the shogunate forces claimed another victory. Several more small forts and villages were attacked before the siege of Osaka Castle itself began on 4 December.

The Sanada-maru was an earthwork barbican defended by Sanada Yukimura and 7,000 men, on behalf of the Toyotomi. The Shōgun's armies were repeatedly repelled, and Sanada and his men launched a number of attacks against the siege lines, breaking through three times. Ieyasu then resorted to artillery (including 17 imported European cannons and 300 domestic wrought iron cannons) and men digging under the walls.

During this siege, the Tokugawa forces also deployed irregular auxiliaries such as Ninja clans from Iga province under the lead of Ii Naotaka, the head of Ii clan. Aside from Naotaka's ninja troops, there were also other Iga ikki warriors under Hattori Hanzō, and Yamaoka Kagetsuge. Aside from the ninja forces, other irregular elements from Iga province such as Tōdō Takatora's Musokunin" (part time samurai) also fought in this battle.[3] [4]

Bombing of Osaka Castle

Ieyasu, realizing that the castle would not fall easily and after consulting with his top advisers, ordered a limited bombing which began on January 8, 1615. For three consecutive days, his forces bombarded the fortress at 10 o'clock at night and at dawn. Meanwhile, miners were making tunnels under the walls and arrows were thrown inwards with messages requesting the surrender of the occupants. By January 15, with no response from the besieged, Ieyasu began an incessant bombardment that had a mainly psychological effect to diminish the morale of the defenders. The stone bases of Japanese castles were invulnerable to the artillery of the era and the structure of the castle remained virtually undamaged.

Realizing that the defenses were extremely strong, Ieyasu tried to convince Sanada Yukimura to change sides. Yukimura, who felt a strong antipathy for Ieyasu, rejected the bribe and made the attempt public. Ieyasu then bribed another captain, a commander named Nanjo Tadashige, asking him to open the castle gates. The attempted treason was discovered and Nanjo beheaded, so Ieyasu changed his strategy. Ieyasu ordered his men to deliberately bomb Yodo-dono's quarters, and when they had found the range, a cannon hit its target, killing two of her maids.

During the night of the 16th, Ban Naotsugu, in charge of the defenses of one of the west side doors, carried out a night attack on the troops of Hachisuka Yoshishige, killing several enemies before retreating. The bombing continued the next day, on the mournful anniversary of Toyotomi Hideyoshi's death. Ieyasu thought that on that day Hideyori would be in the temple dedicated to his father, so he ordered that his forces fire towards the place. The projectile almost hit Hideyori's head, hitting one of the pillars of Yodo-dono's quarters. She became terrified and pressed to reach an arrangement with the shogunate.

Peace negotiations

On January 17, Ieyasu sent Honda Masazumi, accompanied by Lady Acha, to meet with Kyōgoku Tadataka, son of Ohatsu, younger sister of Yodo-dono. During the meeting, Lady Acha assured Ohatsu that Ieyasu had no ill will to Hideyori and that he wished to forgive him, but Hidetada was stubborn about taking the castle, so he had thousands of miners working in tunnels under the pits. On the other hand Honda assured that Ieyasu would allow Hideyori to keep Osaka as his fief, but in case he wanted to leave he would give him another one with higher income, besides that all his captains and soldiers would be given free transit when leaving or they could stay inside if they wanted to, but he would need some hostages as a sign of goodwill.

Ohatsu conveyed the terms to Yodo-dono who, in terror, asked Ōno Harunaga, Oda Nobukatsu, and Hideyori's top seven advisers to accept the terms of the surrender. Lady Acha and Honda met again with Ohatsu, Lady Aeba and Ōkurakyō no Tsubone (Yodo-dono's former wet nurse and one of the most influential figures in Osaka castle), and they told him that the outer pit should be filled by Ieyasu's men. On January 21, the Oda delivered their children as hostages and Hideyori sent Kimura to Chausayama to close the agreement. Ieyasu issued a document, sealed with blood from his finger and signed also by Hidetada, which said:

(that) the rōnin in the castle are not found guilty; that Hideyori's income remain the same as before; that Yodo-dono is not asked to live in Edo; that if Hideyori chooses to leave Ōsaka he may choose any other province as his fiefdom; that his person is inviolable.
On January 22, Ieyasu received a solemn oath from Hideyori and Yodo-dono that Hideyori would not rebel against Ieyasu or Hidetada and that he would consult any matter directly with him. Both Honda Tadamasa and Honda Masayuri were entrusted to dismantle the castle's exterior defenses, so the soldiers of the shogunate tore down the walls and filled the outer moat. Hideyori did complain indignantly to the workers that this had not been part of the arrangement, but the response he received was that they only followed Ieyasu's orders. Honda Masazumi blamed the workers for having misunderstood their instructions because they were already filling the interior moat as well. Although the work stopped momentarily, soon the soldiers of the shogunate continued, so Yodo-dono sent one of her bridesmaids and Ōno to Kyoto. Several days later Ieyasu gave an elusive official response, where he assured that since he had signed an eternal peace, the walls were not necessary.

During the process of reconciliation, Oda Nagamasu, one of attendant of Osaka castle since before the war, leave the castle and sent his child to the Tokugawa shogunate as a hostage and worked hard to reconcile the Toyotomi side with the shogunate. It was argued that even from the start of war, Nagamasa was working for in Ieyasu's favor to seek peace between the two factions.[5] According to Sunpu-ki record, the Toyotomi clan during this time were divided in three factions:

  1. The first faction were led by Ōno Harunaga. This faction favored reconciliation with the shogunate.
  2. The second faction were led by Kimura Shigenari. This faction largely indecisive in their attitude.
  3. The second faction were led by Chōsokabe Motochika. This faction consisted of political War hawks who favored continuing the war.

In the end, Nagamasu decided to leave the Osaka castle as he cannot maintain the reconcilliatory faction's voice within the Toyotomi clan.[6]

End of the peace treaty

Ieyasu left Osaka for Kyoto on January 24, meeting with Emperor Go-Mizunoo at a formal hearing on the 28th, where he informed the emperor that the war had come to an end. Hidetada remained in place to supervise the work of destruction of the defenses, arriving in Edo on March 13. By then, news reached the capital that the Toyotomi camp was once again seeking to enlist rōnin into its service. This information led Ieyasu to order Hideyori to relinquish and abandon the Osaka fief.

Even from the moment when peace was being signed, the Toyotomi command proposed to launch a night attack on the Tokugawa camp, although it was finally decided not to do so. Shortly after Hideyori began to receive reports of the true intentions of Ieyasu, so they began the work of digging out the moats and recruiting troops. Hideyori and his main generals agreed that unlike the first campaign, this time it would be appropriate to take the offensive. Also, it was arranged to secure the areas surrounding Osaka and take Kyoto to control the emperor, so that he would declare Ieyasu to be a rebel against the Imperial throne. Following the rumors of what the Toyotomi army planned, the population of Kyoto began to flee from the city, and even a commander of the shogunate, Furuta Shigenari, was sentenced to death, suspected of being part of a plot to burn down Kyoto and apprehend the emperor.

Through his agent, Gotō Shōzaburō, who infiltrated Osaka to gather information on March 12, Ieyasu learned that the Toyotomi has stockpiled rice and kept employing the rōnin mercenaries in Osaka. In response to these reports, Ieyasu issued ban on March 14 to prohibit ships loaded with annual rice from landing in Osaka and selling their provisions, which was implemented particularly to the daimyo governors from western regions of Japan such as Kyushu and Shikoku. facing with those bans, the Toyotomi side began to show signs of internal division due to the problem of rōnin mercenaries roaming in Osaka. Hideyori was troubled that the ever-increasing number of rōnins, prompting a temporary solution by providing them with gold and silver to stop them from running wild, although at the expense of the Toyotomi clan financially. Meanwhile, Ono Harunaga voiced his disagreement with financing the Rōnin as now they had a peace treaty with the Shogunate. Nevertheless, Hideyori decided to allocate most of their trading profits from the Port of Osaka to finance these rōnins despite the crisis. Furthermore, Hideyori tried to solve this problem by requesting one of the neighboring provinces to be handed to him to increase the tax incomes during the meeting with Ieyasu on March 15. However, his request was rejected, causing unrest in Osaka as the provisions in the city became less day by day. Hideyori expressed his decision to move from Osaka to Koriyama in Yamato Province, as Ieyasu instructed which agreed by his vassals. However, the rōnin threaten that if he did that, they will keep fighting Ieyasu even without Hideyori and commit suicide, forcing Hideyori to gave up his decision and agreed with their decision to fight the Shogunate once more.[7]

Ieyasu left Shizuoka on May 3 to Nagoya, where his ninth son married on the 11th of the same month in the castle of that city. The next day he met a traitor from the Toyotomi camp, Oda Yuraku, who informed him that there were several factions within the castle, that the war councils rarely ended in anything conclusive and that Yodo-dono generally intervened in all matters. Later, he went to Nijō Castle, where he arrived on May 17 and met there on the 21 or 22 with Hidetada, who arrived with the troops ready to go to Osaka.

Summer campaign

In April 1615, Ieyasu received word that Toyotomi Hideyori was gathering even more troops than in the previous November, and that he was trying to stop the filling of the moat. Toyotomi forces began to attack contingents of the Tokugawa forces near Osaka. On 26 May (Keichō 20, 29th day of 4th month) at the Battle of Kashii, Toyotomi forces under the command of Ono Harufusa and Ban Danemon engaged with forces of Asano Nagaakira, an ally of the Shōgun. Tachibana Muneshige, who now served as military advisor of the second shogun, Tokugawa Hidetada, as his military strategist and in charge of guarding the area.[8] Muneshige correctly predicted the movements of the general of Toyotomi, Ono Harufusa's troops and guided Hidetada's troops.[9] Toyotomi forces sustained heavy losses and Ban Danemon was killed.

On 2 June (Keichō 20, 6th day of 5th month), the Battle of Dōmyōji took place. Toyotomi forces tried to stop the enemy approaching from Yamato Province along the Yamato-gawa river. Two Toyotomi generals, Gotō Matabei and Susukida Kanesuke, were killed in the fighting. Toyotomi forces commander Sanada Yukimura engaged in a battle with Date Masamune forces, but soon retreated towards Osaka Castle. Tokugawa forces did not pursue Sanada. The same day Chōsokabe Morichika and Tōdō Takatora battled at Yao. Another battle took place at Wakae around the same time, between Kimura Shigenari and Ii Naotaka. Chōsokabe's forces achieved victory, but Kimura Shigenari was deflected by the left wing of Ii Naotaka's army. The main Tokugawa forces moved to assist Todo Takatora after Shigenari's death, and Chōsokabe withdrew for the time being.

Fall of Osaka Castle

After another series of Tokugawa victories on the outskirts of Osaka, the summer campaign came to a head at the battle of Tennōji. Hideyori planned a hammer-and-anvil operation in which 55,000 men would attack the center of the Tokugawa army while a second force, 16,500 men led by Kyōgoku Tadataka, Ishikawa Tadafusa, and Kyōgoku Takatomo, would attack them from the rear.[10] Meanwhile, Ii Naotaka has send his Red Demon ninja unit under the lead of Miura Yo'emon, Shimotani Sanzo, Okuda Kasa'emon, and Saga Kita'emon to aid the Tokugawa's regular soldiers in storming the southern gate of Osaka castle. Another contingent waited in reserve. Ieyasu's army was led by his son, the Shōgun Tokugawa Hidetada, and numbered around 155,000. They moved in four parallel lines, prepared to make flanking maneuvers of their own. Mistakes on both sides almost altered the outcome of the battle, as Hideyori's rōnin split off from the main group, and Hidetada's reserve force moved up without orders from the main force.[10] In the end, Hideyori's commander Sanada Yukimura was killed by Nishio Munetsugu,[11] destroying the morale of the Toyotomi Army. The smaller force led directly by Hideyori sallied forth from Osaka Castle too late, and was chased right back into the castle by the advancing enemies; there was no time to set up a proper defense of the castle, and it was soon ablaze and pummeled by artillery fire.

The people who were in the castle began to escape. Hidetada knew that his daughter was in the castle, so he sent Ii Naotaka to save her. Senhime managed to escape with her son Toyotomi Kunimatsu (Hideyori's son) accompanied by other women. Kaihime fled with Hideyori's concubine, Oiwa no Kata, and Hideyori's daughter Nāhime. While they retreated, Kaihime personally defended Nāhime from Tokugawa troops. Hideyori and Yodo-dono took refuge in a fireproof warehouse, as much of the castle was in flames. Ōno Harunaga sent Hideyori's wife, Senhime, with his father Hidetada to be forgiven, and to plead for the life of her husband and mother-in-law. Without waiting for answers, Toyotomi Hideyori and Yodo-dono committed seppuku in the flames of Osaka castle, thus ending the Toyotomi dynasty. When the death of the clan leaders was announced, Lady Okurakyo, Lady Aeba, Ono Harunaga, Ono Harufusa and other loyal retainers committed suicide shortly thereafter.

The final major uprising against Tokugawa rule was put to an end, leaving the shogunate unchallenged for approximately 250 years.

Theory

According to an account by an employee of the Dutch East India Company in Hirado, several daimyō set the castle on fire and attempted to defect to Ieyasu. Hideyori executed them by throwing them off the castle wall but could not extinguish the fire, which then led his suicide. The account also stated that about 10,000 people perished in the blaze.[12]

Aftermath

Hideyori's son Toyotomi Kunimatsu, aged eight, was captured by the Tokugawa forces and beheaded in Kyoto. According to legend, before his beheading, little Kunimatsu bravely blamed Ieyasu for his betrayal and brutality against the Toyotomi clan. Nāhime, daughter of Hideyori, was not sentenced to death. Ohatsu and Senhime were able to save Nāhime's life and adopted her; she later became a nun at Kamakura's Tōkei-ji. Hideyoshi's grave, along with Kyoto's Toyokuni Shrine, were destroyed subsequently during the Tokugawa shogunate. Chōsokabe Morichika was beheaded on May 11. There are also records of pillaging and mass rapes by Tokugawa forces at the closing of the siege.

The bakufu obtained 650,000 koku at Osaka and started rebuilding Osaka Castle. Osaka was then made a han (feudal domain), and given to Matsudaira Tadayoshi. In 1619, however, the shogunate replaced Osaka Domain with Osaka Jodai, placed under the command of a bugyō who served the shogunate directly; like many of Japan's other major cities, Osaka was for the remainder of the Edo period not part of a han under the control of a daimyō. A few daimyō including Naitō Nobumasa (Takatsuki Castle, Settsu Province 20,000 koku) and Mizuno Katsushige (Yamato Koriyama, Yamato Province 60,000 koku) moved to Osaka.

The Toyotomi clan was then disbanded.

After the fall of the castle, the shogunate announced laws including [13] (one province can contain only one castle) and Bukeshohatto (or called Law of Buke, which limits each daimyō to own only one castle and obey the castle restrictions). The shogunate's permission had to be obtained prior to any castle construction or repair from then on. Many castles were also forced to be destroyed as a result of compliance with this law.

Despite finally uniting Japan, Ieyasu's health was failing. During the one-year campaign against the Toyotomi clan and its allies, he received wounds that significantly shortened his life. Roughly one year later on June 1, 1616, Tokugawa Ieyasu, the third and last of the great unifiers, died at the age of 75, leaving the shogunate to his descendants.

In popular culture

The siege is the subject of the Hiroshi Inagaki's historical drama "Ōsaka-jō monogatari" (engl. The Tale of Osaka Castle, UK; some other English titles: "Daredevil in the Castle", "Devil in the Castle", "Osaka Castle Story") (1961) with Toshiro Mifune in the leading role.[14] It is also the backdrop for Tai Kato's musical film Brave Records of the Sanada Clan (1963).[15]

The fall of Osaka is (for most of the characters) the final level in the Samurai Warriors series, also serving as the climax of Hattori Hanzō's, Ieyasu's and Yukimura's stories. Called the "Osaka Campaign", it compiles all the battles of the Winter and Summer Campaigns. In the computer game , the siege of Osaka castle is the setting of the first (and demo) mission.

The siege of Osaka also is the main setting for the tv show, .

The protagonist, Tsugumo Hanshirō, of the film Harakiri, mentions his status as a veteran of the siege of Osaka Castle.

The events of the siege and its fallout form the backstory for the 1974 Toei TV series Unmeitōge.

The siege campaign serves as the setting for the video game Nioh's final two DLC. The game's second DLC, "Defiant Hope", is set during the Winter campaign whereas the third DLC, "Bloodshed's End", is set during the Summer campaign up through the fall of Osaka castle and the beginning of the Genna Era.[16]

See also

Appendix

Bibliography

Notes and References

  1. Web site: Daimon Watanabe (渡邊大門) . 大坂の陣でなぜ全国の大名たちは誰一人として豊臣方に味方しなかったのか⁉ . Why did not a single daimyo from across the country side with Toyotomi during the Siege of Osaka? . rekishijin . Abc Arc, inc. . 9 June 2024 . Ja . 2023 . From the January 2024 issue of Rekishijin: 12 Mysteries of the Battle of Osaka; written by Watanabe Daimon.
  2. Web site: Daimon Watanabe (渡邊大門) . 大坂の陣で徳川家康は「大坂城」の築城担当者に攻略の分析をさせていた⁉ . During the Siege of Osaka, Tokugawa Ieyasu had the people in charge of building Osaka Castle analyze the strategy . rekishijin . Abc Arc, inc. . 9 June 2024 . Ja . 2023.
  3. Book: 254: 藤堂藩を裏で支えた無足人 . Rekishi Kaido Promotional Council . 11 May 2024 . Ja.
  4. Book: Iwata Nishizawa . Japan in the Taisho Era In Commemoration of the Enthronement . 1917 . Scarthin Books ABA, ILAB . Cromford, United Kingdom . 695 . 11 May 2024 . En.
  5. Web site: Daimon Watanabe (渡邊大門) . 織田有楽はなぜ大坂城を去ったのか?【前編】 . Why did Oda Yuraku leave Osaka Castle? [Part 1] . rekishijin . Abc Arc, inc. . 9 June 2024 . Ja . 2021.
  6. Web site: Daimon Watanabe (渡邊大門) . 織田有楽はなぜ大坂城を去ったのか?【後編】 . Why did Oda Yuraku leave Osaka Castle? [Part 2] . rekishijin . Abc Arc, inc. . 9 June 2024 . Ja . 2021.
  7. Web site: Sengoku-his Editorial Department . 大坂の陣の最中にあった束の間の和睦期間 真田幸村の手紙、そして再戦(夏の陣の勃発)までのいきさつとは? . What happened during the brief period of peace during the Osaka Siege, Yukimura Sanada's letter, and the rematch (the outbreak of the Summer Siege)? . 戦国ヒストリー . sengoku-his.com . 11 June 2024 . 2017 . Masaru Hirayama, "Three Generations of the Sanada" (PHP Institute, 2011); Masaru Hirayama, Sanada Nobushige: The Truth About the Man Called Yukimura (Kadokawa, 2015); Shin-Jinbutsuoraisha Co.,Ltd. "Sanada Yukimura: Ambition! The Battle of Osaka" (Shinjinbutsu Bunko, 2010).
  8. Book: Takamoto Shimei . 立花遺香 銀台遺事 銀台拾遺 (日本偉人言行資料) . 1916 . National History Research Association . 111-112 . 30 May 2024 . Ja.
  9. Book: 著者参謀本部 . 『日本戦史・大坂役』. "Japanese War History: The Battle of Osaka" . 1893 . 元真社 . 30 May 2024 . Ja . (補伝 第二百三十宗茂の卓識) / Supplementary Biography No. 230: The Brilliant Knowledge of Muneshige.
  10. Book: Turnbull . Stephen. Stephen Turnbull (historian) . 2012 . Illustrated by Richard Hook . Osaka 1615: The Last Battle of the Samurai . Bloomsbury Publishing . 9781846037993 .
  11. Book: 真田幸村の最期に新説、越前松平家の古文書で発見. 2013-02-25. Yomiuri Shimbun.
  12. News: Document on 17th century 'Siege of Osaka' found in Dutch national archives . The Mainichi . 2016-09-22 . 22 September 2016.
  13. Book: Jennifer Mitchelhill. Castles of the Samurai: Power and Beauty. 2003. Kodansha International. 978-4-7700-2954-6. 67.
  14. https://www.imdb.com/title/tt0055267/ The Tale of Osaka Castle
  15. Web site: Sanada fūunroku. Japanese Cinema Database. ja. 30 October 2010. dead. https://web.archive.org/web/20101031185308/http://www.japanese-cinema-db.jp/details/9420. 31 October 2010.
  16. Web site: 仁王 . 2023-03-10 . 『仁王』公式サイト.