Keying is actually the name of this junk a relatively recent reconstruction by the Exeter Maritime Museum. A few words about this type of ship universally known and emblematic of the Asian seas. The Junk could very well have been classified among the ancient ships since it was developed from the rafts of the Chinese Neolithic and other flat-bottomed boats used on the Yang-Tse Kiang and its tributaries. Since then, its base has steadily improved to reach us today almost unchanged. The bimillenary coaster, the Junk, of the ancient Chinese Chu'an, but known to the Arabs under his Malay name, Djong, already had 100 ap. J.C. features the most modern features, including the axial rudder, bamboo sails easy to stir, and a flat-bottomed shell in prismatic shape, with the rear part wider than the front. The junks were used for fishing as well as for transport or war. These vessels were slow, relatively manoeuvrable, though unable to tack, and especially able to ascend the rivers very upstream.
At the end of the Middle Ages, more and more imposing junks appeared, with the aim of trading with neighboring countries of China. In the 12th century, the junks called "steamships of silk", and the first treasure-ship, have five or six masts including two mizzen mounted in tandem on the quarter-deck. They already have three or four bridges and can measure up to 60 meters long for 16 or 18 wide. But the largest of them was built under the reign of Emperor Ming Yongle, for the seven expeditions of Zeng He between 1405 and 1433. (See treasure-boat).