Tenkai, a Buddhist priest in the Edo period who served Ieyasu TOKUGAWA, established Sanno Ichijitsu Shinto, a developed version of Sanno Shinto, after the death of his master and insisted the master's spirit be enshrined by the divine name of Gongen, an avatar of Buddha, according to the principle of Sanno Ichijitsu Shinto (aka Tosho Daigongen).
徳川家康につかえていた江戸時代の僧・天海は、家康の歿後、山王神道説を発展させた山王一実神道（さんのういちじつしんとう）を唱え、山王一実神道に従って家康の霊を権現（東照大権現）の神号で祀るよう主張した。