The documents shed new light on the killing of Empress Myeongseong by Japanese diplomats and military officers – known as “the Eulmi Incident” in Korea – as Tokyo sought to expand its empire and influence across mainland Asia.  

It had previously been thought that early in the morning of October 8, 1895, assassins had tried to storm the palace, pretending to be protecting it under the guise of a fake “pro-Japan coup”.

The empress, the wife of the 26^th king of the Joseon dynasty, is reported to have been hacked to death with a sword and her remains doused with oil and burned, although it is still unclear exactly who inflicted the fatal blows.

Steve Hasegawa, a Nagoya-based expert on stamps, obtained the letters at an antique market and they have been verified as authentic based on their postmarks, how the envelopes were made and their content. 

“The details of the assassination and the accounts of his family in the letters convinced me that they are genuine letters written by Horiguchi,” said Kim Moon-ja, a Korean historian.

“I got a raw feeling of shock reading that a serving diplomat was involved in the killing of the queen of the country to which he was sent,” he told the Asahi newspaper. 

“These are important documents that give us a key to unlock the details behind the incident, of which much is still unknown.”