Sakoku was a policy which was implemented in Japan by the ruling Tokugawa shogunate during the 1630s. It isolated the country from the rest of the world due to a suspicion of Westerners and the spread of Christianity into Asia.
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 (Tokyo) and demanded a trade agreement. The resulting end of seclusion led to Japan modernising rapidly. (AUDIO: The Barbarians and the Samurai)