The Tokugawa shogunate ruled Japan in the 1630s. They implemented the policy of Sakoku, isolating the country from the rest of the world due to a suspicion of Westerners and the spread of Christianity into Asia. Tokugawa Ienari was the Shogun when the First Doctor visited Japan in the 19th century with Ian Chesterton, Barbara Wright, and Susan Foreman.
By the 19th century, the policy had stunted Japan's growth and development. In the mid-19th century, United States warships entered the harbour in Edo and demanded a trade agreement. The resulting end of seclusion led to Japan modernising rapidly. (AUDIO: The Barbarians and the Samurai)