The Life of Date Tanemune

There were many uprisings and downfalls during the Sengoku period of Japan. Everyone was under the rule of the Ashikaga shogunate but because the shogunate couldn’t keep an eye of everything outside the capital, it was easy for daimyos to try their luck and take nearby lands to expand their area of power. Most of the daimyo or clan leaders did this through battles and war. In the case of Date Tanemune though, he used a different approach to expand his influence and gain territory along the way.

By ? (仙台市博物館) [Public domain], via Wikimedia Commons

Date Tanemune and His Family

Date Tanemune was born in the year of 1488. He was the eldest son of Date Hisamune and Sensu’in and in his childhood, he was known by the name Jiro. He grew in the ways of the samurai and served as a Japanese samurai warrior for his clan in his early years. Much like the majority of the firstborn males born into clans during those times in Japan, upon the death of their fathers, they inherited leadership of their respective clans as well as titles if there are any.

By Alvin Lee [CC BY-SA 4.0 (], from Wikimedia Commons

In the case of Tanemune, upon the death of Hisamune in the year of 1514, he became the daimyo of the Mutsu Province or Oshu. Back then, this area was comprised of what is now known to be the Fukushima, Miyagi, Iwate, and Aomori Prefectures. Also included in this area were some portions of the Kosaka and Kazuno which are both a part of the Akita Prefecture. It was a huge parcel of land which made it clear just how powerful the Date clan was at that time.

Despite growing up in the environment of a samurai warrior, it was pretty evident that this man was more of a lover than a fighter. In total, he had 6 lovely ladies in his life. Teishin’in was his wife and from this union came forth 3 beautiful daughters and 3 manly sons. 2 of the 3 daughters he had with Teishin’in were married to Souma Akitane and Ashina Moriuji, respectively. As for his boys, they were Date Harumune, Date Genbanmaru, and Osaki Yoshinobu.

Aside from his wife, he had 5 concubines in his life. They were Nakajo-dono, Shimodate-dono, Nakadate-dono, Watari-dono, and Bo-dono. He had children with each of these women. Nakajao-dono was able to give Tanemune Date Sanemoto. Shimodate-dono was able to give him 3 daughters, who were married to the likes of Nikaido Teruyuki, Tamura Takaaki, and Kakketa Toshimune, along with a son named Date Munetoshi. Nakadate-dono was able to give birth to 2 boys who were namely Yanagawa Munekiyo and Ogata Tasuaji. Watari-dono also gave Tanemune 2 children who were namely Watari Motomune and Watari Tsuname. Bo-dono was also able to give him 5 children who were namely Kori Munesada, Kasai Ishirumaru, Gorakuin Munesake, Date Shichiro, and Kosugo Gozen. Kosugo Gozen, who was his only daughter with Bo-dono, would end up marrying Soma Yoshitane.

The Reign of Date Tanemune

By English: thesandiegomuseumofartcollection (Flickr) [Public domain], via Wikimedia Commons

It is necessary to get familiar with Date Tanemune’s huge family because it will really be a vital part in understanding how he handled being the head of their clan as well as the daimyo to the Mutsu Province. In the year of 1522, he was honored as not only the daimyo of the Mutsu Province but also the shugo or protector of the province. He was also the head of the Date clan that created the Date family House Code which was called the Jinkaishu.

It was mentioned earlier that Tanemune was more of a lover than a fighter. At first, considering the number of children and love interests this guy has had in his life, you can easily assume that he was known as more of a lover than a fighter for this reason. Digging deeper into the events of his life would show you otherwise because there are several other occasions that this character or aspect of himself was proven to be fact and not fiction and a perfect example of such a situation is the time he intervened in the business of the Osaki family.

The Osaki were a powerful family in the Mutsu Province but since the year of 1536, they were recorded to have internal problems that lasted years. It got to the point that they had to ask the warlord of their land, which was Tanemune, to aid their family in this mess. It wasn’t clearly specified what Date Tanemune did to help but it resulted in him giving his second son to become the heir to the Osaki clan. This is why, if you noticed earlier, Date Tanemune had a son with Teishin’in who was named Osaki Yoshinobu.

This act brought the family of Osaki under the influence and control of Date Tanemune and he didn’t even have to hurt anybody. It was this particular way of solving problems that really confirmed the fact that he was a lover and not your usual fighter. This was a rare occasion on all accounts because during those times in Japan, power, and control of land was not and could not be taken without bloodshed and yet Date Tanemune did just that. There were events in the past wherein the daughter is given to an opposing clan to cement or seal an alliance made but in this case, it was completely different.

It was a great way to go about it but this method would also be the death of him in the end. In the year of 1542, he once again tried to gain influence over the Uesugi clan. He did so by announcing that he intended to have his 3rd son, Sanemoto, adopted by the said clan. Unfortunately for him, his firstborn, Harumune, disagreed with his plan. This created a rift in their clan and it was so epic that it was actually given a name. That incident was referred to as the Tenbun no ran.

Basically, their staff and members had to choose a side they wanted to standby. Naturally, Tanemune took an early lead because of the experience he has but the tides turned when Harumune was able to get the support of the Soma and Ashina families.  This loss pushed Tanemune to retire and hand over the leadership of the clan to Harumune. Sadly, it did more than that because the rift tremendously made their clan weaker as a whole.

The Aftermath of His Reign

By Nagamati [CC BY-SA 3.0 (], from Wikimedia Commons

Date Harumune took the place of his father in the year of 1548. Like his father, Harumune had a lot of offspring. Unlike his father, they were all from one woman which was his wife, Kubohime. He had 11 children, some of which were Date Terumune, Rusu Masakage, and Kokubu Morishige. In a way, he too was a lover more than a fighter because he hardly participated in any battles or wars. He knew that the Tenbun no ran took a heavy toll on his clan which is why he spent his reign trying to recover the lost influence the Date clan once had. He moved their clan’s capital to the Yonezawa castle and it was there that he attempted to reestablish themselves as a powerful clan.

He was a very wise leader because he knew how to learn from the past. This could be seen with how he handled his son, Terumune, who became very involved with the work and responsibilities of being a head of a clan early on. As his son got wiser, they argue about decisions more often and since he had already experienced what a rift between a father and a son can do to a clan, he peacefully retired when the time came for his son, Terumune, to be the next head of their clan. After all, if he did decide to let history repeat itself and have another Tenbun war between them, it would be his life’s work that would be flushed down the drain if they lost the influence he worked so hard to give back to their clan.

The life story of Date Tanemune is a very interesting one to share and learn about because it is unique. The usual stories you hear of during this time in Japan usually involves a lot of wars and bloodshed but in the case of Tanemune, it was all about marriage and adoption in a way. Although the Tenbun war created by his unwillingness to heed his son’s advice brought their clan down, his conviction to his believes was still very commendable as it showed that he was not easily swayed by external influences. He was a great clan leader and learning about him and what he went through is a great way to see what kind of people lived during the earlier eras of Japan. They weren’t all obsessed with war and the existence of Date Tanemune can prove this on any day.