These maps are detailed with regard to the rivers, the Great Wall and the travel routes, and include informations on the human presence. The oceans are inhabited by mythical creatures with three heads or gold teeth.
For the Ming, the final catastrophe happens during the 17th year of the Chongzhen Emperor, 1644 in our calendar. Beijing is caught by the Manchus. In the north, a rebel creates the Shun dynasty that will last one year. In the south, the loyalists hope to found a new capital in Nanjing.
The map by Cao Junyi is the last Ming map. Printed in xylography at Nanjing in the early summer of the final year of Chongzhen, it is certainly subsequent to the suicide of the emperor.
This large map 125 x 125 cm is carefully made without being particularly innovative. The title in Chinese referring to the nine border towns probably means a military purpose but it is already too late to save the Ming. The southern resistance against the Qing will however last 18 years.
Three copies of Cao's map are known. One of them is estimated £ 300K for sale by Christie's in London on December 1, lot 181.