In the late Ming period,Xu Guangqi and other Catholic literati were actively involved with military affairs because of the invasion of the Manchu forces and the threat of uprisings.The story of how they imported European cannons and gunners from Macao is now quite famous.However,the introduction of European fortifications,mainly the trace Italienne,in the same period is still relatively unknown.Xu Guangqi and his student Sun Yuanhua exerted considerable efforts in advocating European-style bastions.Xu not only received help from Jesuits,but also support from some Fujianese who were familiar with Intramuros,the Spanish walled city of Manila.In addition to Xu and Sun,Han Lin and Han Yun (also Xu’s students) prepared a Chinese treatise on European fortification architecture based on Italian sources and tried to put the knowledge into practice.Another relevant figure is Ma Weicheng,who allegedly directed the building of 32 angled bastions in three cities around 1640.Although a few recorded writings and practices of constructing European-style fortification appeared in the first half of the seventeenth century,soon afterwards the art of trace Italienne met its end prematurely in China.To a great extent,the swift collapse of the Ming dynasty eliminated the possibility of spreading the new defense technology.Throughout the eighteenth century,the Qing dynasty enjoyed long-term peace,and the warfare at the frontiers brought few threats to the city walls.There was thus little urgency to develop innovative defensive works and European fortification sunk into oblivion until the mid-nineteenth century.