it notified Nicolas Couckebacker, the head of the Dutch East India Company in Japan, of its intentions. About 10,000 samurai were prepared for the expedition, and the Dutch agreed to provide four warships and two yachts to support the Japanese ships against Spanish galleons. The plans were cancelled at the last minute with the advent of the Christian Shimabara Rebellion in Japan in December 1637. Seclusion (1640–1840) The Dutch's cooperation on these, and other matters, would help ensure they were the only Westerners allowed in Japan for the next two centuries. Following these events, the shogunate imposed a system of maritime restrictions (海禁, kaikin), which forbade contacts with foreigners outside of designated channels and areas, banned Christianity, and prohibited the construction of ocean-going ships on pain of death. The size of ships was restricted by law, and design specifications limiting seaworthiness (such as the provision for a gaping hole in the aft of the hull) were implemented. Sailors who happened to be stranded in foreign countries were prohibited from returning to Japan on pain of death. A tiny Dutch delegation in Dejima, Nagasaki was the only allowed contact with the West, from which the Japanese were kept partly informed of western scientific and technological advances, establishing a body of knowledge known as Rangaku. Extensive contacts with Korea and China were maintained through the Tsushima Domain, the Ryūkyū Kingdom under Satsuma's dominion, and the trading posts at Nagasaki. The Matsumae Domain on Hokkaidō managed contacts with the native Ainu peoples, and with Imperial Russia. Many isolated attempts to end Japan's seclusion were made by expanding Western powers during the 19th century. American, Russian and French ships all attempted to engage in relationship with Japan, but were rejected. These largely unsuccessful attempts continued until, on July 8, 1853, Commodore Matthew Perry of the U.S. Navy with four warships: Mississippi, Plymouth, Saratoga, and Susquehanna steamed into the Bay of Edo (Tokyo) and displayed the threatening power of his ships' Paixhans guns. He demanded that Japan open to trade with the West. These ships became known as the kurofune, or Black Ships. Barely one month after Perry, the Russian Admiral Yevfimy Putyatin arrived in Nagasaki on August 12, 1853. He made a demonstration of a steam engine on his ship the Pallada, which led to Japan's first manufacture of a steam engine, created by Tanaka Hisashige. The following year, Perry returned with seven ships