<P> The rise of modern archeology has contributed much to the study of the Great Wall, either in corroborating existing research or in refuting it . However these efforts do not yet give a full picture of the Great Wall's history, as many wall sites dating to the Period of Disunity (220--589) had been overlaid by the extant Ming Great Wall . </P> <P> Western scholarship of the Great Wall was, until recently, affected by misconceptions derived from traditional accounts of the Wall . When the Jesuits brought back the first reports of the Wall to the West, European scholars were puzzled that Marco Polo had not mentioned the presumably perennial "Great Wall" in his Travels . Some 17th - century scholars reasoned that the Wall must have been built in the Ming dynasty, after Marco Polo's departure . This view was soon replaced by another that argued, against Polo's own account, that the Venetian merchant had come to China from the south and so did not come into contact with the Wall . Thus, Father Martino Martini's mistaken claim that the Wall had "lasted right up to the present time without injury or destruction" since the time of Qin was accepted as fact by the 18th - century philosophes . </P> <P> Since then, many scholars have operated under the belief that the Great Wall continually defended China's border against the steppe nomads for two thousand years . For example, the 18th - century sinologist Joseph de Guignes assigned macrohistorical importance to such walls when he advanced the theory that the Qin construction forced the Xiongnu to migrate west to Europe and, becoming known as the Huns, ultimately contributed to the decline of the Roman Empire . Some have attempted to make general statements regarding Chinese society and foreign policy based on the conception of a perennial Great Wall: Karl Marx took the Wall to represent the stagnation of the Chinese society and economy, Owen Lattimore supposed that the Great Wall demonstrated a need to divide the nomadic way of life from the agricultural communities of China, and John K. Fairbank posited that the Wall played a part in upholding the Sinocentric world order . </P> <P> Despite the significance that the Great Wall seemed to have, scholarly treatment of the Wall itself remained scant during the 20th century . Joseph Needham bemoaned this dearth when he was compiling the section on walls for his Science and Civilisation in China: "There is no lack of travelers' description of the Great Wall, but studies based on modern scholarship are few and far between, whether in Chinese or Western languages ." In 1990, Arthur Waldron published the influential The Great Wall: From History to Myth, where he challenged the notion of a unitary Great Wall maintained since antiquity, dismissing it as a modern myth . Waldron's approach prompted a re-examination of the Wall in Western scholarship . Still, as of 2008, there is not yet a full authoritative text in any language that is devoted to the Great Wall . The reason for this, according to The New Yorker journalist Peter Hessler, is that the Great Wall fits into neither the study of political institutions (favoured by Chinese historians) nor the excavation of tombs (favoured by Chinese archeologists). Some of the void left by academia is being filled by independent research from Great Wall enthusiasts such as ex-Xinhua reporter Cheng Dalin (成 大林) and self - funded scholar David Spindler . </P>

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