関ヶ原の戦い Battle of Sekigahara

  In June of 1600 Ieyasu suspected a rebellion, when Aizu's Uesugi built a castle without permission and began to expand his army.
  Ieyasu requested Kagekatsu to come up to Edo to explain himself, However, he refused to comply
  Therefore Ieyasu saw Kagekatsu as a rebel and ordered the daimyos to subjugate the Uesugi clan.

  On June 16 Ieyasu left Osaka and went to Aizu. On the way there, there seemed to be many dangerous developments throughout Kinki, Ieyasu ordered Mototada Torii to guard Fushmi Castle.
  On the way, Ieyasu enjoyed the practice of falconry, On July 2 after the half moon, he entered the fortress of Edo Castle.
  One after another, Ieyasu received reports of the events in the west, at last on July 7, he issued a command to attack Aizu、About 80,000 soldiers under his command started the attack towards Aizu.

  When Ieyasu arrived at Oyama in Shimotuke on July 25, he received the report that Mitsunari and others had started an attack on Fushimi Castle.
  On July 26.Ieyasu realized that a final battle was near, Ieyasu held a council of war and discussed before and after measures (the Oyama rating)
  The forces under the command of military commanders who had favored followed Ieyasu.
  Their wives and children were being held hostage in Osaka Castle by the WESTERN ARMY. Ieyasu asked the military commanders which course of action to take from the camp of Ieyasu.

  However, the strong general Masanori Fukushima who favored Toyotomi left his wife and children there. He decided to defect and fight against the disloyal retainer Mitsunari Ishida. Therefore he announced that he would work with Ieyasu.
  As a result, Nagamasa Kuroda and many others generals promised Ieyasu their support and joined the campaign.
  Kazutoyo Yamauchi of Enshu Kakegawa announced that he would open his castle. Furthermore, generals from Kiyosu along Tokaido also offered.
  Masanori was said to offer 200,000 koku of food from the Kiyosu Castle.

  Ieyasu used the discord between the vassals of Toyotomis by the Oyama rating well.
Ieyasu left Hideyasu Yuki his second son, with Masamune in Utsunomiya to guard from Kagekatsu Uesugi and Yoshinobu Satake. Hidetada Tokugawa led the Nakasendo forces, his army of 38,000, and left for Mino via Kiso for Ieyasu.
  As the Tokai forces with 40,000 soldiers of Masanori Fukushima and others went westward again from Oyama to Tokaido, Ieyasu decided to leave for Edo Castle with an army of 30,000 himself.

  Yoshitsugu Otani began to march from Tsuruga on July 2, he was going to go to the front line for the Aizu conquest. On the way he dropped in at the Tarui mansion of Tamehiro Hiratsuka known for his courageousness.
  Upon hearing this, Mitsunari invited Yositsugu and others to SawaYama Castle and confided in them his secret plan to subjugate. They said“Ieyasu Tokugawa has the trend in the world, It only hastens the collapse of the Toyotomis.”but he wouldn't listen.
In July 11, Yoshitugu was to be bound with Mitunari, who was faithful to Toyotomi. In addition, Yoshitugu had a long-time friendship with Mitsunari. Yoshitugu’s leprosy worsened, he could not see, and walking was difficult.
  With his days numbered, Yositugu made up his mind to give the Toyotomis and Mitsunari his help.

  Mitsunari confided a plan to raise an army for the subjugation of Ieyasu to Nagamori Mashita and Ekei Ankokuji, a military monk of the Mori clan.
  And, on July 12, Mitsunari held a meeting with Yoshitugu, Ekei and Nagamori at SawaYama Castle.
  At the meeting, “Mitsunari asked the great daimyo Terumoto Mori, who was next to Ieyasu, to accept the office of commander-in-chief of the WESTERN ARMY, and to detain many generals who were going to participate in the Aizu subjugation forces.
  Also to forbid the children and wives of the daimyos, who had conquered the east in the Uesugi conquest, to return home and to select some hostage.”

  On July 12 Terumoto Mori took office. Then five days later, he entered Osaka Castle, and became the commander-in-chief of the WESTERN ARMY.
  On the same day, three magistrates Geni Maeda, Masaie Natsuka, and Nagamori Mashita sent a manifesto to the daimyos of Kansai. It said “Although Hideyoshi was asking us to take care of Hideyori until just before his death, Ieyasu has already begun to do as he pleases. If you do not forget favor of Hideyoshi, I will want you to exert loyalty to Hideyori.”
  Following the manifesto, Hidemoto Mori, Hideie Ukita, Hideaki Kobayakawa, Konishi Yukinaga, Yoshihiro Shimazu, and Toyohisa Shimazu with a large number of generals, gathered, a military power approximately 100,000 soldiers.

  The WESTERN ARMY compared favorably with the EASTERN ARMY. But in reality, there were a lot of daimyos in the EATERN ARMY who belonged to the WESTERN ARMY
  For example Ieyasu asked Yoshihiro Shimazu and Toyohisa Shimazu to take Fushimi Castle. They went to Mototada Torii, who was entrenched in Fushimi Castle, and asked for entrance into the castle, which was rejected, therefore they joined the WESTERN ARMY.
  Hideaki Kobayakawa communicated secretly with Nagamasa Kuroda of the EASTERN ARMY , Yasuharu Wakisaka also communicated secretly with Takatora Todo.
  In addition, the important of Terumoto Mori was divided into Hiroie Kikkawa of the Ieyasu group and Ekei Ankokuji of the Mitsunari group and affiliations became complicated.
  Shigekatsu Maeda, Katsushige Nabeshima and others were going to participate in the Aizu subjugation forces. They gave it up because Mitsunari established the barrier in Echigawa, and so they participated in the WESTERN ARMY.

  However, the hostage missions ended in failure. Many generals' wives and children escaped from Osaka Castle and Fushimi Castle, before they were taken to Osaka Castle.
  Tadaoki's wife Gracia refused to become a hostage. When Gracia prepared to commit suicide, one chief retainer, who served as suicide assistant, set off an explosive in the residence. The hostage operation failed because of this fierce incident.