Complex sentence: In 1639, after supressing a rebellion blamed on the Christian influence, the ruling Tokugawa shogunate retreated in a isolationist policy, the Sakoku or "locked state", and contact of Japan with Westerners was restricted to Dejima island.
Split into simpler sentences: In 1639, after supressing a rebellion blamed on the Christian influence, the ruling Tokugawa shogunate retreated in a isolationist policy, the Sakoku. During this "locked state" contact of Japan with Westerners was restricted to Dejima island.