In the autumn of 1614, Sanada Yukimura, invited by the Toyotomi family, came out of the mountain and joined the Toyotomi family in the fight against Tokugawa Ieyasu. This invitation ignited the flame in Sanada Yukimura's heart, and since the defeat of the Sekigahara War in 1600, Sanada Yukimura and his father Sanada Masayuki have been imprisoned by the Tokugawa family in Mount Kudo, and it has been 14 years now. Sanada Masayuki died in this captivity, but Sanada Yukimura held back, expecting a chance to take revenge on the Tokugawa family and prove his ability.
Today's invitation from the Toyotomi family is the opportunity that Sanada Yukimura dreamed of, and Sanada Yukimura immediately secretly led people from Mount Kudo to Osaka in October of that year. Because Sanada Yukimura and his father Sanada Masayuki defeated Tokugawa Hidetada, son of Tokugawa Ieyasu, during the Sekigahara War, he was warmly welcomed and valued by the Toyotomi family and became a general and military division of the Toyotomi family. At that time, the Toyotomi family could already feel the imminent war, so they were actively preparing for the war, and Sanada Yukimura also proposed many battle plans.
Sanada Yukimura , who was a member of the Takeda clan ( a vassal of the Takeda family ) , was so fond of fighting in the wilderness in terms of tactics as a whole , so he proposed many tactics for taking the initiative to confront the Toyotomi army. Considering the balance of strength between the Toyotomi and Tokugawa clans at that time, this plan was rejected by a group of generals led by Later Fuji Kiji and changed to hold Osaka Castle. However, Sanada Yukimura was a famous general in Japan's post-Sengoku period, and he immediately proposed a plan to build an outer castle on the south side of Osaka Castle to strengthen the defense of Osaka Castle.
Sanada Yukimura's suggestion was for a reason, or it was very much in line with the actual situation at the time. Osaka Castle's terrain is unique, with the Seto Inland Sea to the west and several tributaries of several rivers to the north and east, and the terrain is very complex, so it is not an ideal location for troops. Only the open terrain to the south, lacking a natural defense line to rely on, was very vulnerable to attack by the Tokugawa Army. Therefore, if you want to defend Osaka Castle, you must build an outer castle on the outskirts of the castle as a defensive barrier for Osaka Castle. In this regard, both Kiji Goto and Yukimura Sanada took note of this and were also in charge of the construction of the outer castle.
However, Goto Kiji and Sanada Yukimura had a dispute over who would preside over the construction and defense of the outer castle, and basically hoped that they could command the defenders of the outer castle. It was also at this time that rumors spread that Sanada Yukimura was defending the outer castle to the south, and that he intended to cooperate with his brother Sanada Nobunaga, who was in the Tokugawa Army, to bring the Tokugawa Army into the castle. For this sudden rumor, Goto Kiji immediately refuted it, believing that Sanada Yukimura could never be sentenced, and voluntarily gave up the construction and command of the outer castle, leaving the matter to Sanada Yukimura to take full responsibility.
It turned out how right Kiji Goto was. Sanada Yukimura quickly completed the design of the outer castle, an outer castle located south of Osaka Castle, with trenches dug on three sides and rows of fences outside the trenches. There is a firing port every 1.8 meters on the city wall, and facilities such as arrow towers and observation decks are also set up. To put it bluntly, this outer city was basically an insurmountable defensive barrier at that time, and if the frontal attack on this outer city would definitely cause heavy losses to the defenders. This outer castle was later known as the Sanada Maru, and now it will bring unimaginable nightmares to the Tokugawa Army in this "Osaka Winter Front".
On November 18, 1614, Tokugawa Ieyasu ordered three generals, Bee-suga, Asano Nagasei, and Tadao Ikeda, to lead an attack on Kizugawa Kawa, of the Toyotomi Army. The toyotomi defenders of Kizugawa were caught off guard and were breached by Wasuga on the 19th. At the same time, the Toyotomi army's fortifications in Imago and Tsuino were also attacked on November 25, and the Toyotomi army sent reinforcements to engage the Tokugawa army in a bloody battle, but also had to retreat because of the strong Offensive of the Tokugawa army. It is equivalent to saying that not long after the battle began, the Toyotomi army was repulsed by the Tokugawa army on all fronts, and could only retreat to Osaka Castle.
Sanada Yukimura was well aware of Tokugawa Ieyasu's thoughts, but he was not willing to sit back and wait for the Tokugawa army to attack, so he simply left the Sanada Maru with a small force of less than a hundred people and began to attack the forward troops of the Tokugawa army. Sanada Yukimura's move was to kill Tokugawa Ieyasu who had reached the front line in one fell swoop, but unfortunately Tokugawa Ieyasu was scheming and never stepped into his trap, so Sanada Yukimura could only change to constantly harassing the forwards of the Tokugawa Army. The harassment became so effective that the Tokugawa army, overwhelmed by it, began an attack on December 3, 1614, only to be emptied, but also to be teased by Sanada Yukimura.
Annoyed, the Tokugawa Army chased all the way to Sanada Maru, and in front of him was Sanada Maru standing in front of Osaka Castle. The Tokugawa general Maeda Toshihari had planned to make temporary repairs and then attack the castle, but Sanada Yukimura had the soldiers shout insults on the city walls, and Maeda Toshiaki, who was ashamed and angry, immediately attacked Sanada Maru. This move was a very wrong decision, because what Sanada Yukimura wanted was for you to concentrate all your forces on Sanada Maru instead of dividing your forces to attack the other walls south of Osaka Castle.
Angry Maeda Toshitenori ordered the Tokugawa army to attack Sanada Maru, but the troops were blocked by a fence in front of the trench. The attacking forces tried to push open the fence and cross the trench to attack The walls of Sanada Maru, but unexpectedly fell into the trap of Sanada Yukimura. Sanada Yukimura immediately ordered the defenders to open fire, and the officers and men of the Tokugawa Army were immediately shot by the defenders, and the general who took the lead in the attack, Okumura Kaori, was also seriously wounded, and many soldiers were beaten into sieves before they could cross the trench. In desperation, the Tokugawa army could only temporarily avoid its peak, so as not to force the siege to bring greater losses.
In the time that followed, the Tokugawa army launched countless strong attacks on Sanada Maru, but the results were heavy losses, and the 160,000 Tokugawa army was actually blocked by the Sanada Maru in the land of projectiles, and for a time it was impossible to retreat. One of the most successful attacks was the Tokugawa Army, with the help of the toyotomi rebel general Nanjo Mototaka, waiting for the opportunity to rush into Osaka Castle at night. However, this attack fell short, because of the improper communication between the two sides, plus the Tokugawa army launched an early attack, so the air damage was not to mention the strength of the troops, and the people who were killed by the Toyotomi army who were waiting for work were turned over.
During the chaotic battle, the Tokugawa army also took the opportunity to attack Sanada Maru, and Sanada Maru's defenders, led by Sanada Yukimura, fought the Tokugawa army to the death. At that time, the Tokugawa army was completely exposed to the fire of the Sanada Maru defenders, and was counterattacked by the Sanada Maru defenders, and the entire formation was destroyed, almost being cut by the Sanada Maru defenders. However, at this time, the generals of the Tokugawa Army refused to retreat for the sake of face, and planned to fight the Toyotomi army to the death. If this continues, it is estimated that the Tokugawa Army will run out of blood and will not be able to defeat Osaka Castle. In the end, it was Tokugawa Ieyasu who personally ordered the retreat, and the various units of the Tokugawa Army withdrew their troops.
Tokugawa Ieyasu, seeing that Sanada Maru was unable to conquer, simply sent Sanada Yukimura's uncle Sanada Yoshimura with his own handwritten letter to see Sanada Yukimura, and said that if Sanada Yukimura surrendered, he would make Sanada Yukimura the daimyō of 100,000 stones. However, Sanada Yukimura directly rejected his uncle, saying that he was appreciated by the Toyotomi family and could not make a move of betrayal. Tokugawa Ieyasu then increased his weight again, claiming that he would give Sanada Yukimura the title of Shinano domain as soon as Sanada Yukimura surrendered. But this time the emissary did not have a chance to speak, because he did not even see Sanada Yukimura and was driven back.
In desperation, Tokugawa Ieyasu gave up the idea of capturing Osaka Castle and instead bombarded Osaka Castle with artillery on December 16. Frightened, the Toyotomi family eventually decided to make peace with Tokugawa Ieyasu. Four days later, an armistice was concluded between the two sides, but Tokugawa Ieyasu demanded that the defenders must add a moat and must dismantle Sanada Maru. This was actually Tokugawa Ieyasu's plan, because he really couldn't put it off and hoped to create favorable opportunities for the next attack. The Toyotomi family did not know what the plan was, and dismantled their own city defense facilities, which doomed the toyo family's demise.
However, the demand that Sanada Maru must be dismantled also shows the success of Sanada Yukimura's strategy in disguise, after all, Tokugawa Ieyasu would not have made such a request if he was not really afraid of Sanada Maru. As a famous general at the end of the Sengoku period, Sanada Yukimura's abilities were fully demonstrated. But this has also become the last glory of his life, because five months later, the Osaka Summer Battle will become the last battle of his life.
Reference: Battle Map: Battle Map, Battle Of Osaka
"Battle of Osaka, the Greatest and Final Warring States Battle"
《Yukimura Sanada Yoosaka Nori》