Oda Nobunaga: A Samurai Warlord Who Began Unifying Japan

Who Was Oda Nobunaga? The Samurai Who Changed Japan

A powerful and genius samurai warlord who pushed forward to end a turbulent era, Oda Nobunaga came closer than anyone before him to unifying Japan—before his life was cut short by assassination at the Honnoji Incident.

Several factors contributed to the success of Oda Nobunaga(1534-1582, 織田信長), including his overwhelming military, strategic, and economic power. Yet above all, it was his rational approach to thinking that drove him to end more than a century of continuous warfare in Japan.

He was close to unifying Japan after a tremendous number of battles throughout his life, but was killed at the Honnoji incident by his retainer, Akechi Mitsuhide, in 1582.

Nobunaga’s Economic Awareness and the Power of Money

Nobunaga was born at Shobata Castle in the Owari Province (present-day western Aichi Prefecture), near Tsushima and Atsuta ports, the junction of the Ise Bay Sea Route, and the three large rivers (Kiso, Nagara, and Ibi). By controlling Tshushima Port, Nobunaga generated enormous revenues from taxes and customs duties. Recognizing the importance of economic power, he later expanded his influence to include Mikuni Port, formerly controlled by the Asakura clan in Echizen (present-day Fukui Prefecture), as well as Lake Biwa, a key route to Kyoto. Through this strategy, he gained control over Japan's major maritime and transport networks.

Furthermore, Nobunaga promoted the revitalization of commerce through free economic activity by implementing policies such as rakuichi-rakuza (free markets and guild abolition) and the removal of toll barriers. In particular, the complete abolition of approximately 380 checkpoints along the route from the mouth of the Yodo River in Osaka Bay to Kyoto clearly demonstrates the thoroughness of his economic policies (Inryōken Nichiroku).

The Turning Point for Nobunaga: the Battle of Okehazama

He was called the "Great Fool" in his youth because his behavior was unconventional. However, these experiences bore their future fruits. At the age of 27, Nobunaga carefully and logically planned is strategy and achieved a remarkable victory at the Battle of Okehazama. He defeated Imagawa Yoshimoto, the powerful ruler of Suruga Province (present-day Shizuoka Prefecture), who was renowned as "The Best Archer." Despite facing an army of over 25,000 soldiers, Nobunaga led only 2,000 elite troops. Among them were Maeda Toshiie, leader of the Red Horo Shu (Nobunaga's elite unit), and Sassa Masanari, leader of the Black Horo Shu. Nobunaga quickly emerged in the Samurai world of the Warring States Period (1467-1590).

Tenka Fubu and Kirin Signature

After his victory at the Battle of Okehazama, Nobunaga allied with Matsudaira Motoyasu, later known as Tokugawa Ieyasu (1543-1616, 徳川家康) to secure the eastern front and prepare for battle against the Saitō clan of Mino (present-day Gifu Prefecture) in the north.

After seven years of fierce fighting, Nobunaga defeated the Saito clan and entered their castle. He then renamed it Gifu Castle and began using a seal bearing the slogan of Tenka Fubu (天下布武), meaning rule the realm through military power. Through his letters, he promoted the pacification and unification of Gokinai - the five provinces, including Kyoto and surrounding areas - despite the presence of more powerful warlords.

After the assassination of Ashikaga Yoshiteru, the 13th shogun of the Muromachi shogunate, by his own retainers and powerful warlords such as the Miyoshi clan, the authority of the shogunate effectively collapsed. In this context of political breakdown and endemic warfare, Nobunaga began to use a kao (written seal mark) that featured the character "麟" from Kirin (麒麟), a mythical creature symbolizing a peaceful world.

Nobunaga entered Kyoto under the leadership of Ashikaga Yoshiaki, Yoshiteru's brother, and supported him to become the 15th shogun. After that, Nobunaga defeated his opponents one after another, expanding his territory from Owari and the Kinai region (the area centered on Kyoto and Osaka) to Hokuriku (the coastal region along the Sea of Japan, including present-day Fukui, Ishikawa, and Toyama Prefectures), and others.

Nobunaga Amid Unceasing Warfare

During his invasion of Echizen Asakura territory, Nobunaga confronted the biggest crisis in his life near Kanegasaki Castle, with the Asakura army charging forward in front and the Azai army attacking from behind. Nobunaga was about to be crushed by both, but successfully retreated to Kyoto, then to his Gifu Castle. After that, he defeated both the Asakura and the Azai clans.

In parallel, Osaka Honganji, the head temple of the Jodo Shinshu Buddhism sect, stood in front of Nobunaga. The battles against the Honganji continued for around 10 years. In 1580, Nobunaga finally made a peace agreement with the Osaka Honganji Temple at the order of Emperor Ogimachi and received the temple land, located on the edge of the Uemachi Plateau facing Osaka Bay, as an important traffic point to the west and abroad.

In 1575, Nobunaga and his ally, Tokugawa Ieyasu, attacked and defeated the brave and strong cavalry of the Takeda clan with relentless gunfire at the Battle of Nagashino and Shitaragahara. But the Takeda clan retained and grew its power. Nobunaga was so happy and 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.

Nobunaga appointed Sen no Rikyu (1522-1591, 千利休), as his tea master to conduct tea ceremonies mainly at Myokakuji Temple in Kyoto, showing the Ashikaga shogun's tea utensils to his retainers as a symbol of samurai authority and firm unity for future battles.

Nobunaga, Fallen at Honnoji

In 1582, Nobunaga seized the opportunity to destroy the Takeda clan and swiftly brought about its downfall. However, only 83 days later, he was unexpectedly killed by his vassal, Akechi Mitsuhide, at Honnoji Temple. In this sense, he remained an outstanding Samurai to the very end. At Honnoji, at the age of 49, Nobunaga is said to have chanted and danced Atsumori- just as he had done at the age of 26 before departing for the Battle of Okehazama.

“The fifty years of the human world, one of the six realms of Buddhism, is fleeting and short, so let us live to the fullest without fear of death.”

Under the banner of Tenka Fubu. Nobunaga sought to end the Warring States period though miliray power. While many warlords of the era pursued territorial expansion, Nobunaga stood apart in envisioning Japan as a unified nation. In this sense, he was a singular genius shaped by an age of turmoil.

Map of Places Associated with Oda Nobunaga

Key Locations in Oda Nobunaga’s Life and Campaigns

These locations are closely connected to Oda Nobunaga’s rise to power and his major military campaigns during the Sengoku period.

Timeline of Oda Nobunaga’s Life and Major Events

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
1552	Nobunaga inherits leadership of the Oda family		19
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 Azai and Asakura clans and ousted Ashikaga shogun from Kyoto		40
1575	Nobunaga won against Takeda Clan at the battle of Nagashino	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 and Tokugawa defeated the Takeda clan		49
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 at the Siege of Osaka (Toyotomi clan ended)		-