<P> The total length of the Grand Canal is 1,776 km (1,104 mi). Its greatest height is reached in the mountains of Shandong, at a summit of 42 m (138 ft). Ships in Chinese canals did not have trouble reaching higher elevations after the pound lock was invented in the 10th century, during the Song dynasty (960--1279), by the government official and engineer Qiao Weiyue . The canal has been admired by many throughout history including Japanese monk Ennin (794--864), Persian historian Rashid al - Din (1247--1318), Korean official Choe Bu (1454--1504), and Italian missionary Matteo Ricci (1552--1610). </P> <P> Historically, periodic flooding of the Yellow River threatened the safety and functioning of the canal . During wartime the high dikes of the Yellow River were sometimes deliberately broken in order to flood advancing enemy troops . This caused disaster and prolonged economic hardships . Despite temporary periods of desolation and disuse, the Grand Canal furthered an indigenous and growing economic market in China's urban centers since the Sui period . It has allowed faster trading and has improved China's economy . The southern portion remains in heavy use to the present day . </P> <P> In the late Spring and Autumn period (770--476 BC), Fuchai, King of the State of Wu (whose capital was in present - day Suzhou), ventured north to attack the State of Qi . He ordered a canal be constructed for trading purposes, as well as a means to ship ample supplies north in case his forces should engage the northern states of Song and Lu . This canal became known as the Han Gou (邗 沟, "Han Conduit"). Work began in 486 BC, from south of Yangzhou to north of Huai'an in Jiangsu, and within three years the Han Gou had connected the Yangtze with the Huai River by means of existing waterways, lakes, and marshes . </P> <P> The Han Gou is known as the second oldest section of the later Grand Canal since the Hong Gou (t 鴻溝, s 鸿沟, Hónggōu, "Canal of the Wild Geese" or "Far - Flung Canal") most likely preceded it . It linked the Yellow River near Kaifeng to the Si and Bian rivers and became the model for the shape of the Grand Canal in the north . The exact date of the Hong Gou's construction is uncertain; it is first mentioned by the diplomat Su Qin in 330 BC when discussing state boundaries . The historian Sima Qian (145--90 BC) knew of no historical date for it, placing his discussion of it just after the legendary works of Yu the Great; modern scholars now consider it to belong to the 6th century BC . During the course of the 1990s, people saw the black waters which stank, till a $250 million renovation; which started in 2001, brought back some quality . </P>

Who initiated the construction of the grand canal