The Tokugawa thus celebrated the ancestral religion of Shinto glorified by the monumentally opulent shrines they built at Nikko.
The Tokugawa did not build any shrines outside of Nikko.
mnli hypothesis: The Tokugawa did not build any shrines outside of Nikko. premise: The Tokugawa thus celebrated the ancestral religion of Shinto glorified by the monumentally opulent shrines they built at Nikko.