Conversation so far:
What was one of Miyamoto Musashi's teachings?
Miyamoto Musashi created and refined a two-sword kenjutsu technique called niten'ichi.
What were some of Miyamoto Musashi's other teachings besides niten'ichi?
Today Miyamoto Musashi's style of swordsmanship with a jitte is known as Hyōhō Niten Ichi-ryū.

Question: was he popular?
Self-contained rewrite: Was Miyamoto Musashi popular?