The Battle of Komaki and Nagakute (小牧・長久手の戦い, Komaki-Nagakute no Tatakai), also known as the Komaki Campaign (小牧の役 Komaki no Eki), was a series of battles in 1584 between the forces of Hashiba Hideyoshi (who would become Toyotomi Hideyoshi in 1586) and the forces of Oda Nobukatsu and Tokugawa Ieyasu.
The conflict ended after Oda Nobukatsu made peace with Hideyoshi in November 1584. With Nobukatsu having made peace with Hideyoshi, Ieyasu no longer had a clear justification for continuing the war.
Background
In 1583, at the Battle of Shizugatake, Hideyoshi supported Nobukatsu, the second son of Oda Nobunaga, and defeated Shibata Katsuie, who supported Nobunaga's third son, Nobutaka. After winning the battle, Hideyoshi invited Nobukatsu and other generals to his residence at Osaka Castle, which he had just completed that same year. The meaning of such an invitation was for all the men to pay homage to Hideyoshi, which would reverse the roles between Hideyoshi and Nobukatsu. Therefore, Nobukatsu broke his bonds to Hideyoshi and did not go to Osaka Castle. Hideyoshi offered reconciliation to three of Nobukatsu's chief retainers (Tsugawa Yoshifuyu, Okada Shigetaka and Azai Nagatoki), which led to rumors that they were all in support of Hideyoshi. This in turn led Nobukatsu to become suspicious of the three men, whom he ordered executed on the sixth day of the third month of Tenshō 12 (or 17 March 1584 on the Gregorian calendar) These actions gave Hideyoshi the justification for attacking Nobukatsu and, as a result, Nobukatsu asked Tokugawa Ieyasu for auxiliary forces. The next day, when Ieyasu sent his forces out to battle, it became a battle between Hideyoshi and Ieyasu.
Tokugawa troops took the traditional Oda stronghold of 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.
On March 7, Nobukatsu sent Nobuzumi Oda to Tosa to send a letter to Kōsokabe Chikayasu, informing Chosokabe Motochika of the assassination of his vassals and his breaking off relations with Hideyoshi, and asking for military aid from the Chosokabe clan. The plan was to have Sassa Narimasa in the Hokuriku region attack Toshiie Maeda and Nagahide Niwa, while the Chosokabe would attack Osaka from Awaji while keeping the Mōri clan in check, and cooperate with the Saika Ikki, the Negoro-shū warrior monks, and the Kōsa Hongan-ji Forces to fight the Toyotomi forces simultaneously. In response to Nobukatsu's orders, Ieyasu had already departed from Hamamatsu Castle on the 7th, advanced through Okazaki, Yahagi, Ano, and Narumi, and on the 12th set up camp at Yamazaki.
Hideyoshi feared that the Mōri clan would join the battle, and he kept Ukita Hideie and the Inaba clan forces on guard to anticipate any Mōri movement throughout the campaign against Nobukatsu and Ieyasu.
Early battles
During this conflict, Honda Tadakatsu entered negotiation with the Akai clan, a samurai clan from Tanba Province, which led by Ashida Tokinao, younger brother of Akai Naomasa, as Tokinao aspired for the revival of the Akai clan by contributing with Tokugawa clan. Tokinao then raised an army in Tanba to aid Ieyasu.
On the night of March 8, Hideyoshi sent orders to his subordinates in various regions to prepare for battle as he heard Nobukatsu killed three of his vassals. He also dispatched Tomita Tomonobu to request that Nobukatsu come and explain the situation, but Nobukatsu refused, so on the 15th he gave the order to march to Owari Province. Meanwhile, Nobukatsu gave Matsugashima Castle to Takigawa Katsutoshi, but when Katsuroshi vassals went to claim it, they were refused entry by Tsugawa's vassals, so Katsutoshi and Nagamasa Kozukuri forces surrounded and captured the castle. From there on, Katsutoshi, along with Hioki Daizennosuke, claimed Matsugashima Castle for Nobukatsu. It is also said that Katsuyoshi had been persuaded by Hideyoshi to side with him, but Katsuyoshi refused.
On March 9, Sakuma Nobuhide (Masakatsu) and Yamaguchi Shigemasa, the lords of Kanie Castle, were dispatched to Ise to attack Ise Kameyama Castle, which was defended by Seki Morinobu and his son Kazumasa who sided wirh Toyotomi faction. However, as they were unable to take it easily, they retreated to Mine Castle, which was under repair. Nakagawa Taketada (Sadanari) and Seki Jingobei headed to Ise as reinforcements.
On March 10, Hideyoshi invited Mizuno Tadashige, Niwa Ujitsugu, and Takagi Sadatomo, who were on Oda Nobukatsu's faction, to join him as vassals, but they did not accept. In the same day, Nobukatsu requested assistance from Ikeda Tsuneoki of Ōgaki Castle in Mino and Mori Nagayoshi of Kaneyama Castle. but Hideyoshi also sent his own vassal, Bitō Tomonobu, to persuade the two. Discord arose within the Ikeda family, but Iki Tadatsugu urged Hideyoshi to help. Hideyoshi then sent Tsuda Hayatosa (Nobuyuki) to further persuade them, promising them the three provinces of Mino, Owari, and Mikawa as a reward. In the end, the Ikeda and Mori clan declined Nobukatsu's request and joined Hideyoshi. On the other place, Oda Nobukage, Hori Hidemasa, Gamō Ujisato, Hasegawa Hidekazu, Hineno Hironari, and Takigawa Kazumasu attacked Mine Castle with over 10,000 soldiers. Because the castle's defenses were insufficient, Sakuma Nobuhide decided to attack, but was ambushed by Takigawa Kazumasu and defeated, with Seki Jingobei killed in battle. Nobuhide abandoned the castle and retreated.
In March 13, Tasashige and his son Mizuno Katsunari were ordered to rescue Kobe Castle in Ise. Tadashige attacked the position of Okada Yoshitada, the younger brother of Okada Shigetaka (who was executed by Nobukatsu), forcing him to surrender and capturing it. On the other place, Inuyama Castle, which had been left thinly defended due to a reinforcement mission to Ise, was suddenly attacked and occupied by Ikeda Tsuneoki son, Motosuke. Nakagawa Seizonosuke, who was in charge of the castle, was defeated and killed. In March 14, Nakagawa Yutada was hurriedly returning to Inuyama when he was assassinated by Ikejiri Heizaemon, who had targeted him out of personal vengeance. Upon learning of the fall of Inuyama Castle, Sakai Tadatsugu and Mizuno Tadashige joined the defense of Kuwana Castle to anticipate further attack from the Toyotomi faction In Mino.
Meanwhile, in the same day, Nobukatsu met with Ieyasu at Kiyosu Castle to hold a strategy meeting, and Sakakibara Yasumasa stepped forward and proposed building a fort at Komakiyama, on the border between the Oda and Tokugawa clan as the headquarters. The remains of a castle from Nobunaga's time were on Komakiyama, which later nearly completed in March 22. After that Nobukatsu returned to Nagashima Castle to defend Ise.
Battle of Haguro
On March 16, Mori Nagayoshi, who was envious of his father-in-law, Tsuneoki's military achievements, advanced beyond Inuyama Castle and set up camp at Hachimanbayashi in Haguro with his military inspector Bitou Tomonobu, hoping to achieve some success of his own. On March 21, Hideyoshi left Osaka with a large army and entered Inuyama Castle on the 27th. On the 28th, Ieyasu also entered Komakiyama, leaving Kiyosu Castle in the hands of Naito Nobunari and Miyake Yasusada, and the next day, Nobukatsu joined the camp at Komakiyama. At the same time, Mori Nagayoshi, began his attempt for the Kiyosu Castle. Sakai Tadatsugu, who was already scouting the Nagayoshi forces' movement for certain time, discovered their position and immediately received permission from Ieyasu to attack. Sakai had Amano Yukimitsu guide him, and at dawn the next day, he launched a surprise attack with Matsudaira Ietada, Matsudaira Ienobu, Okudaira Nobumasa, and Honda Yasushige. Okudaira crossed the Gojo River and began his charge, but Mori and Bitou fought bravely and pushed them back. However, as they pursued the retreating enemies too far, they were ambushed from behind by Tadatsugu's detachment and his men, resulting in confusion among Nagayoshi's soldiers. This caused Mori Nagayoshi to retreat, having suffered 300 casualties.
One of Nagayoshi's officer, Noro Munenaga, was killed by Matsudaira Sadaharu. However, they ultimately failed to entrap Nagayoshi as he managed to break through the encirclement and retreat. Following this, Tadatsugu returned to Komaki where he, Honda Tadakatsu, and Ishikawa Kazumasa stationed their troops.
By March 18, vassals Nishio Yoshitsugu and Abe Masakatsu jointly sent a reply to Toyama Sadonokami, reporting that they had defeated Mori Nagayoshi in the Battle of Haguro on March 17, killing over 1,000 Nagayoshi's soldiers. In response to this news Kushihara Toyama, Sado no Kami, and Hanzaemon-no-jo switched sides to Nobukatsu and Ieyasu, facing off against Mori Nagayoshi, who was on Hideyoshi's side. Learning of Nagayoshi's defeat at the Battle of Haguro, they launched an attack on Akechi Castle. Ieyasu dispatched Toyama Toshikage. On April 8, they also attacked Iwamura Castle.
Stand off at Mount Komaki
After the battle of Haguro, Ieyasu occupied Komakiyama Castle on March 18 and constructed forts and earthworks around it to prepare for the Hashiba army. Hideyoshi left Osaka Castle with 30,000 soldiers on March 21, advanced to Gifu on around March 21 or 27. On April 4, Hideyoshi also built a fort on Mount. Iwasaki and established his headquarters at Rakuden Castle. Both sides built numerous forts.
On April 8, Tadashige led the vanguard of the Oda-Tokugawa allied forces, along with Okanaga Nagamori, Osuka Yasutaka, Sakakibara Yasumasa, Honda Hirotaka, and Niwa Ujitsugu. At a military council held at Obata Castle, Tadashige proposed a strategy to avoid the enemy's main force and rather attacking the Toyotomi army's rear. Sakakibara and other generals agreed and commence Tadashige's plan. The next morning, they attacked Miyoshi Hidetsugu's main camp and routed him. In this engagement, Tadashige's family member, Mizuno Buncho, reportedly manage to Kill enemy general Kinoshita Toshimasa. Hirano Nagayasu also reportedly fought on this battle under Hidetsugu.
On Tensho 12, 13th day of the third month (23 April 1584), Ieyasu arrived at Kiyosu Castle. On that same day, warriors of the Oda clan's vassals who were led by Ikeda Tsuneoki switched to the side of Hideyoshi and took over Inuyama Castle, which had originally been built by Oda Nobunaga.
Meanwhile, Takigawa Katsutoshi received reinforcements from Tokugawa general Hattori Hanzō, as he held out against Hashiba Hidenaga's siege. However, within a month, he was cornered to the Ninomaru (second bailey of the castle), and after a hard fight, he surrendered the castle on the condition that the lives of his soldiers be spared.
Through his wife, Keihō-ni, Katsutoshi negotiated with the besieging forces to be allowed to safely leave the castle.
Hidetsugu's expedition
Hideyoshi and his troops left his fortifications at Osaka Castle on the 21st day (1 May), while Hirano Nagayasu fought at the Battle of Futaebori castle before retreating.
On May 4, Hideyoshi inspected the area and ordered preparations for a flood siege of Takegahana Castle. He ordered the first attack on Kaganoi Castle in Mino, where Kagai Shigemune and his son Shigemochi were holed up . The Hashiba forces of Nagaoka and Gamou attacked fiercely, and the defenders requested peace, but their demands were not accepted. So, in the early hours of the 6th, they opened the castle gates and charged out. Later, Hideyoshi arrived at Inuyama Castle on the 27th day (7 May).
On May 9, Oku Castle which was defended by Oda Nobuteru, who was on Nobukatsu's side, surrendered. On the May 10, the levee was completed, and Takegahana Castle was completely surrounded and submerged. On May 11, there was an incident where Oda Nobukatsu's vassal, Sakuma Michinori, suddenly attacked Ichijo-cho in Kyoto and attempted a rebellion. While the Shoshidai (deputy governor), Maeda Gen'i , was away to Owari Province. Onogi Shigetsugu, who was stationed in Yodo in Yamashiro, immediately led 300 soldiers and quickly put down the rebellion. Michinori fled. Although the rebellion was unsuccessful, it makes Hideyoshi furious and led to a major confusion involving the Emperor, the Imperial Court, and the Hongan-ji Temple.