Ieyasu came to support Kyonyo, and after experiencing espionage on the night before the Battle of Sekigahara (it was sensed by the Mitsunari ISHIDA side and was encountered in such a dangerous situation that he had written a farewell poem, but with the help of Hidenobu ODA and others and hard fighting by his followers, he at last returned to Kyoto), he erected Shinshu-honbyo Mausoleum in Karasuma in Shichijo in Kyoto in 1602, with Imperial sanction from the Emperor Goyozei in the background.
家康は教如に肩入れすることとなり、関ヶ原の戦い前夜の諜報活動（これが石田三成方に察知されて、辞世の句を認めるほど危険な目にも遭ったが、織田秀信らの協力や門徒の奮戦もあって無事帰洛を果たしている）を経て1602年、後陽成天皇の勅許を背景にして京都七条の烏丸に真宗本廟を建立した。