Located in the town of Odawara in Kanagawa Prefecture, Japan, Odawara Castle is a national heritage and a popular tourist destination for travelers from both in and outside of the country. It’s only an hour-long train ride from Shinjuku station and therefore it is one of the most accessible national heritage sites from Tokyo.

Although it is one of the most incredible historical sites of Japan, its value is difficult to decipher even for the average Japanese due to its complicated history. So here’s a simple and neat explanation to why Odawara Castle is oh-so fascinating.

1. Where the most exciting era of samurai warriors started, and ended

Odawara is where the most popularly studied and learned portion of Japanese history – the Sengoku era (which literally translates to “the war-time” era) – all started.

1-1. Background

Until 1493, Japan was ruled by a single, Middle Age feudal government, which means the samurai lord with the most amount of land (the Shogun) called all the shots in politics of Japan, and allowed less influential lords to rule small pieces of land in different parts of the country. At this time, the center of politics was in Kyoto.

A strict, top-down hierarchy between the Shogun family and all the other lords was kept for over 300 years. Although in practice the Shogun had greater power than the emperor, he was technically “chosen” by the emperor to rule Japan. So the organization looked like this:

However between 1467 and 1493, the Shogun family went through a series of internal conflict and finally resulted in a coup d’etat by a subordinate of the Shogun, HOSOKAWA Masamoto. HOSOKAWA then put a relative of the Shogun on the thrown.

This meant the Shogun family’s great power was split in two ways between supporters of the old Shogun and supporters of the new Shogun, and were too busy hating each other to care about what happened outside Kyoto, and pretty soon, the lesser lords scattered around the country started to obey less to the Shogun’s directives.

It was as if a great big family-owned business like Toyota was split into two halves (which is hard to imagine), and fed up by the internal conflict, many of its skilled directors started wondering if they should go out on their own.

And it happened. In 1493, a local ruler of the old Shogun’s bloodline was overthrown in Izu Province in Eastern Japan by an influential samurai called ISE Moritoki, or better known as HOJO Sōun (Samurais tended to change their names pretty often). He basically invaded Izu Province to avenge a murder of a member of the new Shogun’s family, and claimed the throne thereafter himself.

He became the first Sengoku Daimyo (lords who were independent from any other lord’s rule and expanded their territory by means of military power. Kind of like an entrepreneur in our world today). The castle HOJO Sōun took was Odawara Castle, the first Japanese castle owned by a Sengoku Daimyo.

Other local feudal lords followed HOJO, started claiming land, invading neighboring territories and therefore became Sengoku Daimyos themselves. And that was the start of the Sengoku era.

1-2. The Sengoku era

The Sengoku era (1493 – 1590) was a 100-year period where hundreds of well-known and legendary samurai warriors and ninjas fought, spied and conspired against each other and competed for the one-and-only throne for the ruler of Japan.

It was a series of all-out fights by means of war, political, social, economic, sexual and even artistic tactics – anything mankind could imagine to elevate one’s position and lower or rid another’s was put into play.

For the lack of a better analogy, it was as if all the legendary NBA basketball players of all time were put onto the same court and were told to score the most number of points within 48 minutes.

Each Japanese prefecture has its own legendary warrior or two (or more) from the Sengoku era and therefore a significant portion of the Japanese population is hyped about this part of their national history.

There are thousands of dramas, movies, novels, manga, video games and mobile apps that use the Sengoku era as a central theme. This part of history is like the Game of Thrones to Japanese people. Knowing the Sengoku era is essential in understanding not only the traditional culture of Japan but also its modern pop culture.

1-3. The climax of the Sengoku saga – Odawara Castle

Anyway, Odawara Castle was not only where the Sengoku saga started, but also where it ended. There were hundreds of castles that were built and destroyed due to warfare all around Japan, but Odawara Castle was one of the very few ones that remained standing for the duration of the Sengoku era – for a whole century.

The era ended when the ultimate winner of the Sengoku race, TOYOTOMI Hideyoshi surrounded Odawara Castle with an army of over 200,000 soldiers for 3 months and made the HOJO family (which had an army of 80,000) surrender in 1590. HOJO Sōun had initiated a 5-generation-long, 100-year reign over Odawara, never to be overthrown until the very end, while over 100 other Sengoku Daimyos rose and fell all over Japan.

Imagine Toyota Motors, after its establishment in 1936, gained strength over time and eventually started acquiring all the car manufacturers in the world including Mazda, Renault, BMW, even Ford and Volkswagen, and Daimler was the very last independent manufacturer standing.

Odawara Castle was the setting of where the last-standing foe to the conquerer of Japan fell.

2. An impossible fort to capture

Odawara Castle used to be a monstrously enormous fort that was impossible to conquer.

2-1. The moats, walls and gates

Castles with moats (or in other words trenches filled with water) were really, really hard to capture in the Sengoku era. The one or two bridges built over the moats were the only passages that led to the castle, and robust walls and a thick gate would shut invaders out. If you visit Odawara Castle, you’ll see numerous slits on the walls – these were where gunmen could safely aim at targets who came close.

Only a few bridges are built over the wide moats of Odawara Castle. Imagine not being sniped by gunmen while trying to cross the bridge. Impossible.
The small slits on the walls are for gunmen to poke out their guns and shoot down invaders.
Gates are devastatingly thick.

Canons were not imported from Western countries until the end of the Sengoku era, and therefore there was no weapon deadlier than a gun. Also, bullets fired from guns then didn’t fly as accurately as bullets do now, so sniping gunmen who peeked outside from the wall slits was extremely difficult, while sniping enemy soldiers trying to cross the bridge from behind the walls was fairly easy.

So if you were a general, there was virtually no way to break into Odawara Castle without losing a whole lot of your men. It’s no surprise that historical documents state that invaders in the past gave up and turned back without even bothering to make an effort to break in.

When you visit and walk around the castle’s premises, it will be fun to try to figure out a way to get to the building the lord would reside, the Tenshukaku, without getting killed. I think you’d agree that you’re looking at a mission impossible.

The Tenshukaku is located in the heart of the castle’s premises.

2-2. The crazy size of the castle

If you go to Odawara by train, you’ll get off at Odawara station and from there, it’s a 10 minute walk to the nearest bridge that will allow you to cross the moat surrounding the castle. Once you cross the bridge, it’s clear that you’ve entered the castle’s premises.

However, the castle that remains today only represents less than a 1/10 of the total area the castle protected. The HOJO family had constructed a 9 km-long moat surrounding the town of Odawara over the course of a 100 years. The area behind the moat was as big as over 75 football stadiums.

After the Sengoku era, the castle was hard-hit by several earthquakes and because peace was attained, many parts of the moat were eventually land-filled.

The whole city used to be behind a 9 km-long moat.

The average size of Sengoku era castles was around 2 to 3 football stadiums big, so we can safely say that Odawara Castle was monstrously big.

Why did the HOJO family bend backwards to build moats of such great lengths? There are a couple of reasons.

A result of the HOJO family’s prioritizing their people

The great moats are partly a result of the HOJOs’ unique political policy.

The Sengoku era was a time in which Daimyos attained and kept control by means of military power and/or showing caliber over their people. The HOJO family was an extreme example of the latter – they exerted love and respect towards the people they ruled.

Agriculture was the primary industry in most parts of Japan at this time in history, and rice was not only staple food but currency for Japanese people. Hence, tax was taken in the form of rice. While it was common for Daimyos around Japan to take away 50% or even 60% of the rice made each season as tax, the HOJOs only took *40%. In case peasants reported corruption of a tax collection officer, the officer was exiled. The HOJOs were very progressive in terms of granting human rights to peasants.

*reference: https://www.hitachi-systems.com/report/cbreak/biz/biz-style-14.html

Whenever a Daimyo family’s territory was invaded by another, it was common for the victimized family to hide behind the castle walls and moats with their soldiers to pass the time – until the opponent gave up and went back home (the reason invaders may sometimes need to give up mid-conquest will be explained later).

In order to lure the defending side out of their castle, the attacking side would often burn houses and rice fields located outside the castle, and/or massacre the peasants who lived there. Storming out from their stronghold to save the peasants would most likely result in losing everything including their own lives, so staying in the castle patiently was the way to go for most Daimyos.

But the HOJOs apparently did not want that to happen, and so built moats all around their kingdom to keep even the then-disposable peasants safe and sound.

The town of Odawara seen from the top of Odawara Castle. Almost everything you see in the picture was behind moats during the HOJOs’ reign.

Tactic to fend off invaders without fail

The extensive moats allowed the HOJO family to fend off enemies without having to shed blood.

During much of the Sengoku era, Daimyo families were served by several samurai families and each family had farmland and peasants who lived and worked there to oversee. The Daimyo and each samurai family had their peasants serve as soldiers whenever it was time to face off other Daimyo forces. So male farmers would wear armor and bring their own weapons to join the Daimyo’s army.

To invade another Daimyo territory, the Daimyo himself, his subordinates and peasant-soldiers sometimes had to walk for weeks or months to get to the battlefield. If the mission was to capture an enemy castle, the campaign tended to take a long time because the most common strategy taken was to surround the castle, cut the enemy’s line of food supply, and therefore starve them until they surrender.

This was often the best course of action because the defending side had a huge advantage being protected by castle walls and moats. Significant casualties were expected if the invader chose to force their way into the castle. Losing soldiers in battle meant losing farmers to grow rice back in the invader’s territory. And so it was best if none died by means of making the opponent surrender.

Moats are virtually wide and deep rivers. If soldiers tried to cross the moat, they would be shot dead from turrets like the one you see in this picture.

But there was a downside to this tactic, and that’s where the HOJOs’ moats covering vast amount of land start to make sense.

Daimyos could not take peasant-soldiers out for battle for too many months. Peasants had to go home to grow rice! If they failed to return in spring, they wouldn’t be able to plant rice, and if they failed to return in autumn, they wouldn’t be able to harvest rice. Not only would the peasants’ family starve but also the Daimyo and his samurais would too because there would be less tax (or more specifically, rice) revenue.

So when a Daimyo invaded another Daimyo’s territory, it was the defending side’s victory if they could stay in the castle for several months because the invaders would have to retreat and go back home eventually. However the defending side would have to withstand the all or most of the following:

  • starvation
  • thirst
  • plague
  • the sight of their children dying from lack of food, water or medicine
  • their peers falling mentally ill from experiencing all of the above
  • Internal dispute among samurais on whether to risk death without fighting or die honorably by fighting

So some Daimyos thought “Hey, why not build castle walls and moats around our farmland too so that we’ll be able to grow food even while being surrounded by invaders?” The HOJOs took this idea to an extreme, and therefore dug moats all around Odawara.

As a matter of fact, neighboring Daimyos had attempted to invade Odawara a few times, but historical records suggest that they all ended up retreating without doing much fighting. During the Sengoku era, each Daimyo constantly had to watch his back when he took his troops out on a military campaign because neighboring Daimyos would be more than happy to invade while a significant portion of his troops was not there to defend. So for this reason too, invaders couldn’t keep surrounding an enemy castle for too long.

The HOJOs were the last to be conquered by TOYOTOMI Hideyoshi, simply because their castle was utterly impossible to capture by conventional means. This leads to the final piece of history that makes Odawara Castle a must-visit.

3. The stage of the greatest war campaign in Sengoku history

Throughout its 600-year history, Odawara Castle has only been torn down by natural disasters. It has never been seized by enemy troops by means of force – TOYOTOMI made the HOJOs surrender by means of displaying a tremendous difference in power, and this was why Odawara Castle became the stage of the greatest war campaign in Sengoku era Japan.

3-1. The outbreak of war

Here’s what Japan looked like in 1590, the year the HOJOs surrendered.

Now you may think it’s obvious the HOJOs didn’t have a chance against TOYOTOMI, but information was not provided so clearly like the infographic above, and there was no Internet to see what people in other parts of Japan would have been tweeting about how much power the TOYOTOMI possessed.

So the HOJOs and their samurais probably didn’t have a true understanding of what was going on in the rest of the world (Kinda like Japan now, which still hasn’t fully internalized the fact that it is no longer the hippest part of the world in terms of economics and technology). Besides, compared to the other Daimyos who were defeated and ended up giving up their sovereignty, the HOJOs were having a pretty good run.

This incapacity to fully grasp the circumstances then is a likely reason that a front-line samurai-commander of the HOJOs went ahead and captured a neighboring castle (called Nagurumi Castle) that belonged to one of the subordinate samurai families of TOYOTOMI in 1589.

TOYOTOMI responded by demanding the HOJOs to turn over the culprit so that he could be beheaded, but the HOJOs decided to protect their commander and refused – another event that suggests the HOJOs were thinking they could fend off TOYOTOMI’s army with their mighty castle in case there was outbreak of war.

Enough reasons were provided for TOYOTOMI to raise arms, and so he gathered a total of over 200,000 soldiers from all over his territory, trampled the smaller castles of HOJO domain within a matter of a few days, and surrounded the massive Odawara Castle from all directions – both from land and sea. The HOJOs had around 80,000 in arms behind their castle walls.

Being totally surrounded by armed men is pretty terrifying, but the HOJOs were still confident because “How could TOYOTOMI possibly feed 200,000 soldiers for months? They are bound to give up if we wait” was what they thought.

But their enemies didn’t budge for 3 months. TOYOTOMI had organized an extensive web of logistics that allowed rice to be transported from all over Japan, and of course, there was no worry for other Daimyos looking to stab TOYOTOMI from behind.

Furthermore, TOYOTOMI had implemented a policy in which peasants were no longer allowed to possess weapons of any sort (which was unheard of until then, and yes, this is why there are no guns possessed in modern-day Japan) and therefore had farmers be farmers and those who were employed as soldiers be soldiers, 2 years prior to the Odawara campaign. This meant there were no more half-farmer half-soldiers in his military, hence ridding the need to travel back home in time for seeding and harvest of rice.

TOYOTOMI could have kept Odawara Castle surrounded for many more months. But he made sure the HOJOs understood who they were challenging.

3-2. Devastation and surrender

TOYOTOMI had no worries in financing his campaign, but of course the sooner the job’s done, the better. His goal was to make the HOJOs surrender without having to fight and cause casualties on both sides. Surrendering without even trying to fight back was considered very unvirtuous among samurais back then, so TOYOTOMI needed to give the HOJOs a good reason to admit that they had absolutely no chance of victory.

So aside from showing a great gap in political, financial and military power (by surrounding Odawara Castle from all directions with his fleets of unforeseen numbers), he decided to show an overwhelming gap in technology.

TOYOTOMI Hideyoshi, by the way, was the Steve Jobs of the Sengoku era. He climbed his way up from being a peasant all the way to the ruler of Japan, mainly thanks to getting results by applying his unconventional, creative ideas. Among his creative skills was communication and showmanship. If he were alive today, we would call him a great presenter.

While he made his commanders station themselves all around Odawara Castle for a couple of months, TOYOTOMI took his own troops to the top of a mountain where he could look at Odawara Castle from above. The mountain was called Ishigaki-yama.

There, he had his men build a castle from scratch, and also instructed that they NOT cut down trees while they were at it. This way the construction was done secretly, as the trees hid the site from the enemies at Odawara Castle.

On the morning after the castle was complete, the trees surrounding the castle on Ishigaki-yama were cut down, and to the eyes of the HOJOs, it was as if a castle, which was definitely not there a night ago, appeared out of nowhere when they woke up one morning.

Odawara Castle was surrounded by an army of over 200,000 men for approximately 3 months.

It was a devastating sight for the HOJOs because not only did a castle appear out of nowhere, but the castle was built of stone walls. Building a temporary fort nearby an enemy castle out of dirt and wood was a common tactic during the Sengoku era. But stone walls were reserved for constructing home-ground castles, simply because it involved a lot of work, time, careful planning and the risk of being attacked while working on it.

Stone walls of Sengoku-era castles looked like this.

TOYOTOMI also employed all the cutting edge technology of fort architecture that was accumulated over decades of conquest in Western Japan. From afar, the HOJOs saw the overnight castle above them and realized how far behind they were in everything. The head of the HOJOs at this hard time, HOJO Ujinao, surrendered to TOYOTOMI, asking for all his men and people to be kept alive and safe in return for his own head (beheading of the family head effectively signified the end of that family bloodline, which was equivalent of a company filing bankruptcy in today’s terms).

TOYOTOMI allowed Ujinao to live as he was married to one of his most important subordinate TOKUGAWA Ieyasu’s daughter, and instead had Ujinao’s father and an uncle (who also had a large say in politics) to be beheaded. Odawara Castle was taken and the region the HOJOs once ruled was given to TOKUGAWA Ieyasu, who eventually became the next ruler of Japan following TOYOTOMI Hideyoshi’s death.

Ujinao was given a much smaller piece of land in a mountainous region. However, possibly from shock of deprivation, Ujinao fell ill and died in the same year he lost everything his ancestors had developed over a course of 100 years.

And that’s the story of Odawara Castle. A LOT of drama.