I've seen this happen even without a daimyo death. Takeda had grown very large, and as Hojo I slowly worked him back till he was only left in Mikawa. I owned Totomi, Shinano, and everything right of that. When I was about to finish off Takeda in his last province, like 7 provinces on the far right coast (note these were NOT recently conquered provinces, but some of the earliest conquered provinces) all revolted for Takeda.



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Koga no Goshi

"Nandai"
Since time began
the dead alone know peace.
Life is but melting snow.