Rise of Toyotomi Hideyoshi after Oda Nobunaga

Historical analyses of the power struggle following the death of Oda Nobunaga focus on the Kiyosu Conference and the subsequent rise of Toyotomi Hideyoshi.

Research indicates that the marriage between Shibata Katsuie and Oichi, often viewed as a defensive union against Hideyoshi, was likely a political arrangement brokered by Hideyoshi himself during the Kiyosu Conference. Historical documents such as the ‘Nanko Zatsuroku’ suggest this union may have been linked to territorial reallocations, such as the exchange of Nagahama Castle. While Hideyoshi initially reached agreements with Katsuie, he later took unilateral actions, including forcing through Nobunaga’s funeral arrangements, which contributed to the eventual conflict.

Hideyoshi consolidated power by championing Sanboshi, Nobunaga’s grandson, as the legitimate successor. This strategic positioning allowed Hideyoshi to secure a leadership role within the Oda hierarchy. As Sanboshi grew, he was granted the name Hidenobu—incorporating a character from Hideyoshi’s name—signifying his integration into the Toyotomi political order. While Sanboshi was eventually granted Gifu Castle, his life was defined by the transition between the Toyotomi and Tokugawa eras.

The rivalry culminated in the Battle of Shizugatake in 1583, a decisive conflict that split the Oda clan’s vassals. A key turning point was Maeda Toshiie’s decision to shift his allegiance from Katsuie to Hideyoshi, establishing him as a cornerstone of the Toyotomi regime. The battle was characterized by extensive fortification networks and saw the rise of the ‘Seven Spears of Shizugatake,’ young generals who gained prominence under Hideyoshi’s favor.