Three Dark Horses Who Dominated the Sengoku Era

Mastering History Creates Future

Yesterday’s article, we provided an overview of the unique historical period known as the Sengoku era, observing how the actions of Sengoku daimyo (戦国大名, warlords) strangely resemble current trends in AI. Today, without going into too many specifics, we’ll focus on three prominent figures who rapidly gained power during this tumultuous time and ultimately achieved Japan’s first-ever unification.

As briefly outlined yesterday, the Sengoku period began with scattered regional power struggles, eventually shifting towards larger, organized forces as stronger daimyo emerged. This marked the beginning of realistic ambitions for national unification. Interestingly, the key players who rose to prominence were initially overlooked, relatively unknown figures: notably, Oda Nobunaga (織田信長), Toyotomi Hideyoshi (豊臣秀吉), and Tokugawa Ieyasu (徳川家康). The emergence of these three dramatically reshaped Japanese history.

To quickly recap the historical flow: first, Oda Nobunaga initiated the conquest of the Kinai region (Kansai), signaling the beginning of nationwide ambitions. However, Nobunaga was ultimately betrayed by his retainer Akechi Mitsuhide (明智光秀) and committed suicide during the Honnoji Incident (本能寺の変). Following Nobunaga’s death, Toyotomi Hideyoshi swiftly defeated the traitorous Akechi and achieved national unification. Thus, Nobunaga’s life effectively ended just shy of full unification. After Hideyoshi’s death, a decisive conflict over succession—the Battle of Sekigahara—occurred in 1600. Tokugawa Ieyasu emerged victorious, establishing the shogunate in Edo, thereby completing the process of national unification. However, even after Ieyasu formally established the Edo Shogunate in 1603, the Toyotomi clan, linked to Hideyoshi, remained formidable, maintaining significant power from their stronghold at Osaka Castle, dominating western Japan. To secure his authority, Ieyasu inevitably needed to eliminate this formidable obstacle. Therefore, Ieyasu initiated two separate wars between 1614 and 1615, ultimately leading to the destruction of the Toyotomi clan.