Battle of Okehazama: A David Versus Goliath Story

On the rainy hills of Dengaku-hazama, thousands of men march for battle. 25,000 Imagawa soldiers and 5,000 (or 2 to 3 thousand depending on the source) Oda soldiers are prepared for combat. Lord Oda Nobunaga clearly has the odds stacked against. He is heavily outmanned by Imagawa forces. Could he even win, or is this an easy defeat for him?

For the past four years, Oda Nobunaga has lead a campaign against the Imagawa clan and clan leader Yoshimoto. The Imagawa clan tremendous power amongst some of the other clans and ruled more land than the Oda. This was mostly due to the adherently strong political ability by Imagawa Yoshimoto. He not only had to deal with Nobunaga’s father, Nobuhide, in the west; but, he also tried his best not to tick off the much more powerful Takeda and Hojo clans to the east (the former of which he married into, much to the latter’s dismay). Yoshimoto did however make a tri-alliance with both Hojo and Takeda. With that out of the way, not from the east would stop Yoshimoto’s plans of going to the west and subsequent victory over the Oda. It is theorized that Yoshimoto was planning to march to Kyoto to insert his control over the shogunate, which at the time had weakening power due to the Ōnin War. Things became good for Yoshimoto when Nobuhide would suddenly die in 1551. Since Nobuhide ruled in a sort of cult of personality, the clan and region went into chaos. However when the seven year succession crisis ended, Nobuhide’s oldest (legitimate) son, Nobunaga, came out as leader of the clan who was the last person anyone in the clan who have expected.

For the next four years, Nobunaga make efforts to beat back Imagawa occupation on the Owari-Mikawa province border. Nobunaga’s main objective was to take the Imagawa controlled castles of Narumi and Odaka. Nobunaga in 1559 would build several fortifications around the area to halt supply lines from Imagawa. Yoshimoto would amass 25,000 men and march out west to Owari, home of the Oda. Yoshimoto’s men would stop to make camp at a hilly area of Okehazama. With a military force of that size marching to the relatively small in power Owari province, many would plead Nobunaga to stay in shelter at Kiyosu castle or even giving up to Imagawa; however, Nobunaga take the third opinion of battling his father’s longtime foe into submission. So after he gave a inspiring speech, he with his men and march towards the area around Narumi castle, to march towards Imagawa Yoshimoto at Okehazama, and to march towards his greatest challenge yet.

On June 12th of 1560, Nobunaga’s troops charged to Narumi castle and made some more fortifications along the way. He knew that the Imagawa forces were scattered and that his only chance of winning was attacking the separated Imagawa units. These units were earlier used to help out Odaka castle with Oda forces, so they would be well tried out. The hills were raining heavily which helped Nobunaga’s forces cover the sounds of troop movement. Yoshimoto made the mistake of not having his scouts patrol the area well enough due to his over-confidence. This gave Nobunaga a chance to ambush the unit that was camping by the nearest road; they were the ones furthest away from the main camp. This went off without a hitch due to Nobunaga posting garrisoned troops near Narumi castle, stopping any aid. After that Nobunaga head south east to attack the main Imagawa camp while chasing after the remaining troops from before, it’s actually was where Yoshimoto was staying at. Yoshimoto’s detachment was around 5,000 “strong” and was wholly unprepared for the surprise attacking Oda force. The rest of Yoshimoto’s men were pre-occupied by the other Oda units that were garrisoned in parts of the area. However, it wasn’t like Yoshimoto’s detachment was all made of greenhorns. Yoshimoto’s guard was made up from trained and very seasoned soldiers with a good amount of normal troops. The Oda forces were also had a good amount of battle expertise from during the Oda succession crisis.

However the sight of the remaining troop from the defeat vanguard unit fleeing from the Oda troops cause a lost in morale in the Yoshimoto detachment, with some troops even fleeing from the battle. This made the rest of the conflict easier for Nobunaga to win. As the battle raged on, the Imagawa line was doing its best to maintain it and their position on the hilltop. With only the guard good enough to handle them for a time, the Oda forces were able to break through parts of the Imagawa line. It was too late; any help from other Imagawa forces wouldn’t be able to help their lord in time. Yoshimoto, knowing how bad this is turning out to be, made a run for Imagawa controlled Kutsu castle with two of his men. Nobunaga (who may or may not have known that he was attack Yoshimoto’s main camp beforehand) realized that Yoshimoto was making a retreat and sent his best samurai, Mōri Shinsuke and Hattori Koheita, to stop him. Yoshimoto’s retreat became hard due to how muddy the area got. This forced him into a last stand against the Oda. Once again, none of the other Imagawa units came in to save their lord despite there being more than enough to do so. The end of Yoshimoto came when he was tackled to the ground by Hattori Koheita and was beheaded. Upon Yoshimoto’s death, the remaining Imagawa troops surrendered or fled.

The battle was a shock to everyone, the brilliant military skill of Oda Nobunaga was able to do what his late father did not. Defeat Imagawa Yoshimoto once and for all with Yoshimoto’s head literally handed to him. The many vassals of Yoshimoto (prominent and otherwise) yield to the victorious stroke of Oda. The following the battle, Nobunaga gained notoriety throughout the region. The small province lead by a man who one time acted as a total cretin years ago, bested his father’s longtime nemesis. This new found fame would lead soon lead to his rise and later plan to unify Japan. Much of the power the Imagawa clan had gain soon started to disappear. Yoshimoto’s successor, Ujizane, failed to keep the clan together and thus the once powerful Imagawa clan had lost their land to two other clans years later. The Matsudaira clan of Mikawa province had for years been under the yoke of Imagawa rule. With Yoshimoto dead the clan’s head, Motoyasu, decided to break away from Imagawa control and would start taking Imagawa land for himself. He would later form an alliance with the man who made this possible, Oda Nobunaga, and would rename himself Ieyasu. The clan itself would soon be renamed into the Tokugawa clan. Okehazama was also were Nobunaga witnessed the capabilities of his sandal-bearer, a man by the name of Kinoshita Tōkichirō, although most people today know him as Toyotomi Hideyoshi. Truly the Battle of Okehazama was not only a turning point for the Oda clan’s war against the Imagawa clan, but it serves as a major turning point for the Sengoku period and Japanese history as a whole.