The Chiba Clan Had Strong Ties with Minamoto no Yoritomo!— Chiba-jo (Shimofusa Province, Chiba)

2026-03-28

To learn more about the history of the Chiba clan

Hello, this is Shin.

On Sunday, May 14, 2023.

I visited Chiba-jo (Inohana-jo) in Chiba City, Chiba Prefecture 🚙

There is a theory that a tenshu (main keep) never actually existed at Chiba-jo,

and that only earthworks and dry moats remained in what is now Inohana Park next to it.

Even so, visiting the site was highly educational for gaining a deeper understanding of the history of the Chiba clan.

Below, I will explain that history with the help of images.

This photo was taken after parking in front of the Chiba City Folk Museum.

Although the tenshu was constructed later, looking up at its magnificent structure still fills me with excitement ✨

From the parking area, you can walk straight to the front of the museum.

There’s no chance of getting lost.

As you may have guessed,

the Chiba City Folk Museum is located inside this tenshu.

That’s often the case with many castle ruins.

The inside of the keep is frequently used as a history museum.

(Admission is free.)

I picked up a brochure at the entrance and headed inside!

First, on the first floor, there are Q&A-style displays like this,

where you can learn in depth about the history of the Chiba clan.

Until I came here, I honestly knew nothing about the Chiba clan myself…

Although the Chiba clan were descendants of the Taira clan, they lent their support to Minamoto no Yoritomo, the leader of the Minamoto clan.

I’ll explain how that came about later.

Then, during the Sengoku period, they sided with the Hōjō clan and were ultimately destroyed along with them in Toyotomi Hideyoshi’s Odawara Campaign.

The Chiba clan’s family crest is also extremely fascinating✨

This “Tsuki-hoshi mon” (moon-and-star crest) welcomed me when I visited Motosakura-jo 😅

For more about Motosakura-jo, which later became the residence of the Chiba clan, please see the article below.

I found myself captivated by the many magnificent exhibits.

From the second floor upward, you can see many exhibits on display.

Armor made of iron introduced from the Europe, like this…

It seems that even musket bullets could not easily penetrate it.

It’s a matchlock gun.

I’d love to try firing one someday… 😅

This is a tachi (long sword).

Seeing it up close, the sharpness of its blade is truly chilling.

Here is a portrait of Minamoto no Yoritomo, the leader of the Minamoto clan, “Genji".

Why did the Chiba clan—descendants of the Taira clan—support the head of the Minamoto, who opposed the Taira?

The commonly accepted theory is that Yoritomo guaranteed the Chiba clan and others control over their lands.

In reality, siding with someone who would secure your territory was a very practical decision.

In history class, I learned about serving one’s lord (“hōkō”) in return for his favor (“go-on”).

It seems that Uesugi Kenshin repeatedly advanced as far as Shimofusa ( Present day, Chiba ).

The Hara clan, who defended Usui-jo, repelled the Uesugi forces!

For more about Usui-jo, please see the article below.

On the fifth floor (the top floor), there was also a banner of the Chiba clan.

“A warrior whom Minamoto no Yoritomo called father” — that sounds impressive ✨

It seems their ties with the Minamoto clan were extremely strong.

From the top floor, you can enjoy a panoramic view of Chiba City.

Most modern (reconstructed) tenshu are built like this, aren’t they?

This is the view from the top floor of the tenshu.

Every time I climb a castle keep, I can’t help but feel as if I’ve become the lord of the castle—surely I’m not the only one who feels that way…

The stone walls and remnants of earthworks that can be seen looking down in this direction.

I’d like to go and take a closer look after this.

The earthworks and ruins that remain within the park

After finishing the exhibits inside the museum,

I stepped outside again.

Here, I filmed a video of the (reconstructed) tenshu and its surroundings.

Near the tenshu, you can also see a statue of Chiba Tsunetane, the founder of the Chiba clan.

A bronze statue standing boldly beside the tenshu.

Hmm… it really looks impressive and striking 😊

A little distance from the statue,

there is a small pavilion (rest area), along with slight remains of Dorui (土塁：earthworks） and Ishigaki (石垣：stone walls）.

This area was likely the original castle site.

This is the view of the tenshu from the castle site.

When you take some distance and photograph it, it gives a different impression.

A little further in from the castle site,

you’ll find stone steps like these.

There was also a stone monument marking the ruins of “Inohana-jo".

It is said that the area of the castle site was named this way because its shape resembled a boar’s snout.

I see—indeed,

when you check the castle site on Google Maps,

the entire area (the green grounds) does look like a boar’s snout.

I found a layout map of Chiba-jo!!

It seems that the area around the earthworks we saw earlier corresponds to Honmaru (本丸：main enclosure),

but the exact location of the Chiba clan’s residence remains unknown.

I took this photo from a little distance away from the main enclosure.

You can also see traces of stone walls and earthworks in the foreground.

A little further along, I came across a teahouse called “Inohana-tei”.

You can enjoy light refreshments here.

According to the layout map we saw earlier, this area may correspond to Ninomaru (二の丸：second enclosure)？

I moved a little away from the teahouse and took another photo.

The area on the right corresponds to Honmaru (本丸：main enclosure).

With that, I headed home.

There were not many remaining structures outside the tenshu,

but I was able to learn a great deal about the history of the Chiba clan.

I would recommend this spot to anyone simply interested in castle keeps,

or to those who want to explore the history of Chiba.

See you next time!🏯

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