Before the early 1600s, many nations were present on the main land of Japan. Traders, missionaries and others from Spain, the Netherlands, Portugal and several other nations were starting to influence Japanese culture. So much in fact, that the ruling upper class became anxious. Tokugawa Iemitsu (1604-1651) was the ruling shogun and eventually banned virtually all foreigners.
In the 1630s he decided to completely shut down the Japanese borders. Since Japan is an island, it was a hard but manageable task. Laws were put in place, which are now referred to as Sakoku. Japans isolation would be extreme: Any Japanese national who went outside of his homeland and returned would be executed. Any foreign national would be prohibited from entering the country. There were only a very few exeptions such as small trading posts in several cities.
Sakoku was in place for over 200 years until American Navy commodore Matthew Perry (1794-1858) started a series of events that would lead to the opening of Japans borders.
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