The island served as a haven for pirates throughout the Qing dynasty (1644-1911). Kinmen was captured by Japan in 1937, then retaken by the KMT government in 1945. After the KMT retreated from the mainland to Taiwan, martial law was declared, and the ROC government made Kinmen its front line of defense. All in all, the military period lasted for about 800 years.
蒙古滅宋之後，宋末志士不願服侍異族他姓而避居此地、明末鄭成功亦曾以此為反清復明基地；清初海寇猖獗、清末日據時代、到國民政府以此地為反共基地，總稱為長達八百年的「軍事時期」。