The great daimyo in Muromachi period, Ouchi Yoshihiro

Ouchi Yoshihiro (1356-1399) was daimyo in Suo, Nagato (these two provinces make the area as current Yamaguchi) and other many provinces at the Muromachi period.
The origin of Ouchi clan is not confirmed, but their ancestors seemed to came from Baekje kingdom in ancient Korea.

In his times, Muromachi shogunate had a problem.
Since before the shogunate founded, the Imperial Court had been separated to the Northern Court and Southern Court.
Muromachi shogunate had supported the Northern Court.
However the Southern Court hold their own Emperor in Yoshino, Yamato province (the area same as current Nara) and had resisted the Northern Court and Muromachi shogunate.
Also influential Kikuchi family in Kyushu region had resisted under the Southern Court.
Muromachi shogunate send Imagawa Sadayo, daimyo of Totomi (western part of current Shizuoka) to suppression Kikuchi clan and Kyushu region.
Ouchi Yoshihiro supported Imagawa Sadayo to defeat Kikuchi clan and warlords under the Southern Court.
This contribution made him to get new domains in Kyushu and Chugoku region.

In 1391, the war of Meitoku broke out.
In the war, a powerful daimyo Yamana family invaded Kyoto.
The war was caused by the provocation of shogun Ashikaga Yoshimitsu.
Yoshimitsu had attempted to undermine powerful daimyo, and made provocation against them.
The war of Meitoku was one of results of that.
Ouchi Yoshihiro fought well to defend Kyoto from the army of Yamana.
After they defeated Yamana, shogun Yoshimitsu took most of Yamana's domains.
From the domains, he gave Izumi (a part of current Osaka) and Kii (a part of current Wakayama) provinces to Yoshihiro as a reward for the fight.

Izumi and Kii adjoined Yamato, where the Southern Court located.
From that, Yoshihiro got a connection to the Southern Court.
Then, Yoshihiro helped the unification of the Northern and Southern Courts in 1392.
This raised his reputation.

Moreover he have traded with Goryeo (a Korean dynasty) and made a large fortune.
Surprisingly, he asked the Goryeo to give him a domain in the area where Baekje existed.
As the reason for that, he claimed he was a descendant of the prince Seimei of Baekje kingdom.
His request wasn't approved, but this episode show us how Yoshihiro had a strong relationship with Goryeo in that times.

However his peak of his power didn't last long.
The relationship between Yoshihiro and shogun Yoshimitsu worsened gradually.
Yoshimitsu worried about the power of Yoshihiro included the relationship with Goryeo dynasty.
Yoshimitsu provoked Yoshihiro, and in 1399, the war of Ouei broke out.
The war located in Sakai, Izumi province and finally Yoshihiro was defeated.

Unfortunately Yoshihiro was killed, but his family survived and later they flourished again.
He got great credit by his lifelong activities.