 The rise of new emperors and new factions diminished such extravagances ; the capture of the Zhengtong Emperor during the 1449 Tumu Crisis ended them completely . The imperial navy was allowed to fall into disrepair while forced labor constructed the Liaodong palisade and connected and fortified the Great Wall of China into its modern form . Wide @-@ ranging censuses of the entire empire were conducted <unk> , but the desire to avoid labor and taxes and the difficulty of storing and reviewing the enormous archives at Nanjing hampered accurate figures . Estimates for the late @-@ Ming population vary from 160 to 200 million , but necessary revenues were squeezed out of smaller and smaller numbers of farmers as more disappeared from the official records or " donated " their lands to tax @-@ exempt eunuchs or temples . Haijin laws intended to protect the coasts from " Japanese " pirates instead turned many into smugglers and pirates themselves . 
