In what became known as the Gapsin Coup, an enlightenment group led by Hong Young Shik, Kim Ok-gyun and Pak Yonghyo, who opposed any Qing interference in Korea's internal affairs, seized the occasion of a ceremony marking the start of operations at the General Office for Postal Administration to stage a coup on December 4; their coup was intended to transform Korea into a constitutional monarchy.
しかし清国の内政干渉を嫌う洪英植、金玉均、朴泳孝らの開化派が朝鮮の立憲君主国家への転換を狙い引き起こしたクーデタ、いわゆる甲申政変は、12月4日にの郵征総局開庁祝賀式典に乗じて事を始めた。