Siege of Osaka

The siege of Osaka (大坂の役, Ōsaka no Eki, or, more commonly, 大坂の陣 Ōsaka no Jin) 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 Genna Armistice (元和偃武, Genna Enbu), because the era name was changed from Keichō to Genna immediately following the siege.
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.
As preparations, Hideyori sent many letters to most of the daimyo lords in Japan who he predicted would sympathize with the Toyotomi clan. However, his efforts were largely fruitless as his letters delivered by his couriers were rejected by many of the recipients. Hachisuka Iemasa at first was hesitant, until his son convinced him to not accept Hideyori’s invitation to rebel against the Shogunate. Meanwhile, Shimazu Tadatsune directly rejected his invitation as Tadatsune stated the Shimazu clan was still recovering from the Sekigahara war and had no intention to stand up against Ieyasu. Tadatsune also returned a sword gift from Hideyori. An envoy of the 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. Furthermore, the Toyotomi clan also failed to convince the Mōri clan under the lead of Mōri Terumoto to join their side, Terumoto instead supported the Tokugawa shogunate, as on November 3, Terumoto ordered his vassals Mōri Motochikazu and Motoyuki Sugimori, who were in charge in Mori Hidemoto's absence, to send half of the troops east if Hidemoto asked them to march out to aid the shogunate in fighting 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 ammunition. In May, a company of British merchants tried to sell lead in Hirado, but failed to find a buyer. This incident was reported by William Adams to the shogunate, who purchased the entire quantity of lead on offer. Furthermore, in the same month a Dutch merchant company was also selling lead, which was also purchased by the shogunate. Later in June, Tokugawa Ieyasu purchased a large amount of cannons, gunpowder, and bullets from British merchants, with Adams acted as the middleman, the prices being 1 kan for cannons, 2.3 bun for gunpowder, and 1.6 bun for bullets.
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 the 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.
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.
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:
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 the attendants of Osaka castle since before the war, left 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. According to Sunpu-ki record, the Toyotomi clan during this time were divided in three factions:
In the end, Nagamasu decided to leave the Osaka castle as he could not maintain the reconcilliatory faction's voice within the Toyotomi clan.
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 had stockpiled rice and kept employing the rōnin mercenaries in Osaka. In response to these reports, Ieyasu issued a 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. Faced with these 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 rōnin, 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 they now 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 rōnin 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 was agreed to by his vassals. However, the rōnin threatened that if he did that, they would keep fighting Ieyasu even without Hideyori and commit suicide, forcing Hideyori to gave up his decision and agree with their decision to fight the Shogunate once more.
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.
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 now served as military advisor of the second shogun, Tokugawa Hidetada, as his military strategist and in charge of guarding the area. Muneshige correctly predicted the movements of the general of Toyotomi, Ono Harufusa's troops and guided Hidetada's troops. 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 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.
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. Meanwhile, Ii Naotaka sent 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. In the end, Hideyori's commander Sanada Yukimura was killed by Nishio Munetsugu, 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.
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 to his suicide. The account also stated that about 10,000 people perished in the blaze.
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 ikkoku ichijō (一国一城) (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.
The siege is the subject of 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. It is also the backdrop for Tai Kato's musical film Brave Records of the Sanada Clan (1963).
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 Shadow Tactics: Blades of the Shogun, 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, Samurai Rabbit: The Usagi Chronicles.
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.