Sengoku period history examined through Toyotomi and Tokugawa dynamics

Historical analyses surrounding the NHK Taiga drama ‘Toyotomi Kyodai!’ provide insights into the political maneuvers of the Sengoku period. One significant event discussed is the defection of Ishikawa Kazumasa, a close aide to Tokugawa Ieyasu, who transitioned to the service of Toyotomi Hideyoshi in 1585. While viewed as a betrayal, researchers suggest the move was successful for Kazumasa, as he was granted 80,000 koku in Shinano Province.

The era was also marked by Hideyoshi’s aggressive recruitment of talent and his strict policies regarding inheritance. Unlike the later Tokugawa system of seniority, Hideyoshi often implemented significant reductions in land holdings (fiefs) when a high-ranking vassal died and was succeeded by a young heir. For example, the son of Niwa Nagahide saw his inheritance drop from 1.23 million koku to 150,000 koku, a reduction of approximately 88 percent.

Additionally, historical accounts note that Hideyoshi’s plans to eliminate the Tokugawa clan were interrupted by the Tensho Great Earthquake in 1585, which caused widespread destruction and forced a temporary diplomatic shift toward familial alliances between the two powers.