How did Oda Nobunaga unify Japan?

Powerful Samurai to push forward to end a turbulent era, but assassinated

A genius Samurai, Oda Nobunaga (1534-1582, 織田信長), pushed forward to end a turbulent era. There are several factors in Nobunaga's success, such as his overwhelming military, strategic, and economic power. But his rational thinking was the driving force behind bringing an end to the warfare that had continued for over 100 years. He was close to unifying Japan after 155 battles throughout his life but was killed at the Honnoji incident.

Nobunaga was born at Shobata Castle in the Owari region, near Tsushima Port, the junction of the Ise Bay Sea Route, and the three Nobi Rivers (Kiso, Nagara, and Ibi). By controlling Tshushima Port, Nobunaga amassed enormous revenues from taxes and customs duties. Recognizing the importance of the economy, Nobunaga, later expanded his control of the port to include Mikuni Port, which was controlled by the Echizen Asakura clan, and Lake Biwa on the way to Kyoto, to gain control of Japan's sea route. He was called the "Great Fool" in his youth because his behaviors were unconventional. However, these experiences bore his future fruits. At the age of 27, Nobunaga prepared carefully and logically and succeeded in defeating the supreme lord of the Suruga province, nicknamed "the best archer", Imagawa Yoshimoto’s large army of more than 25,000 warriors with only 2,000 of his elite troops including two Horo Shu at the Battle of Okehazama. Nobunaga quickly emerged into the Samurai world of the Warring States Period (1467-1590).

Seven years later, once he defeated the Saito clan in Mino (Gifu prefecture) and entered Gifu Castle, he started to use his stamp under the slogan of "Tenka Fubu" in his letters to advocate for the pacification and unification of Japan despite the presence of more powerful military lords. In addition, Nobunaga began to use a Kao (written seal mark) that featured the character "麟" from "Kirin, 麒麟," an imaginary creature symbolizing a peaceful world. This change occurred after Ashikaga Yoshiteru, the 13th shogun of the Muromachi Shogunate, was killed by warlords such as the Miyoshi clan, marking the definitive fall of the Shogunate.

He entered Kyoto under the leadership of Ashikaga Yoshiaki, the 15th shogun. He defeated his opponents one after another, expanding his territory from Owari (Tokai) and Kinai (Kyoto and Osaka) to Hokuriku, Kanto, Shinano (Nagano), Chugoku, and Shikoku. Osaka Hongwanji, the head temple of the Jodo Shinshu Buddhism sect, stood in front of Nobunaga. After around 10 years of battles, Nobunaga made a peace agreement with the order of Emperor Ogimachi. Then, Nobunaga held Japan's first illumination festival at Azuchi Castle. Seeing Azuchi Castle floating in the darkness, many people must have felt a sense of realizing the peaceful world. In addition, in 1575, Nobunaga and Tokugawa Ieyasu forces attacked and defeated the Takeda's brave and strong cavalry with relentless gunfire at the Battle of Nagashino and Shitaragahara. However, Nobunaga was unexpectedly killed by his vassal, Akechi Mitsuhide, at Honnoji Temple in Kyoto in 1582.

While respecting tradition and culture, Nobunaga embodied innovation, abandoning the old ways that made no sense and pursuing rationality. He appointed another innovator, Sen-no-Rikyu, as his tea master to conduct tea ceremonies at mainly Myokakuji Temple in Kyoto, showing Ashikaga Shogun's tea utensils to his retainers as a symbol of samurai authority and firm unity for future battles.

He fulfilled his task as an outstanding Samurai to the end. That is, his head did not fall into Mitsuhide’s hands. Therefore, the rumor, "Nobunaga is alive," spread and circulated among many Samurai, causing many Samurai not to join Mitsuhide. Consequently, Mitsuhide was struck down by Nobunaga’s other right hand, Toyotomi Hideyoshi. “The 50 years of the human world, one of 6 realms of Buddhism, is fleeting and short, so let us live to the fullest without fear of death.” This is a verse from "Atsumori" that Nobunaga chanted and danced before heading off to the battle of Okehazama at the age of 26 and before committing suicide at the Honnoji at the age of 49.

Nobunaga aimed to end the Warring States period with military power under the slogan of “Tenka Fubu. He was, after all, a genius who emerged in the age of the turmoil. Warlords of the Warring States period strove to “expand their territory,” and Nobunaga was the first to offer a vision of Japan as a nation. His way of life still attracts many people today.

Oda Nobunaga Map

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Oda Nobunaga Timeline

1336	Ashikaga Takauji estabilished Muromachi Shogunate	Muromachi Period	-
1467	Onin War started (- 1477)		-
1493	Hojo Soun - the first warlord in Japan history - settled Izu province by defeating Horikoshi Kubo		-
1534	Nobunaga was born in Owari province		Age=1
1560	Nobunaga defeated Imagawa Yoshimoto at the battle of Okehazama		27
1563	Nobunaga built his 1st own Komakiyama Castle		30
1567	Nobunaga moved to Gifu Casle and started to use the "Tenka-fubu" stamp		34
1568	Nobunaga went up Kyoto bringing Ashikaga Yoshiaki		35
1570	Osaka Hongwanji raised the army against Nobunaga		37
1571	Nobunaga defeated Enryakuji Temple's monk solduers		38
1573	Nobunaga defeated the Asai and Asakura clans and ousted Ashikaga Shogun from Kyoto		40
1575	Nobunaga defeated the Takeda Clan at the battle of Nagashino & Shitaragahara	Azuchi Momoyama Period	42
1576	Nobunaga started the constraction of Azuchi Castle		43
1579	The Azuchi Castle Tower was completed		46
1580	Nobunaga made peace with Ishiyama Hongwanji Temple		47
1582	Nobunaga was killed at Honnoji by Akechi Mitsuhide		49
1582	Hideyoshi defeated Akechi Mitsuhide		-
1590	Hideyoshi unified the nation		-
1598	Hideyoshi passed away		-
1600	Tokugawa Ieyasu defeated Ishida Mitsunari, Hideyoshi's right arm at the battle of Sekigahara		-
1603	Ieyasu estabished Tokugawa Shogunate at Edo	Edo Period	-
1615	Toyotomi's Osaka Castle burnt down to the ground at the Summer Siege of Osaka		-