The Asahi Shimbun reports today that a document has been discovered, sent from Annam (Vietnam), and addressed to Toyotomi Hideyoshi using the title “King of Japan” (日本国王). The announcement comes from the Kyushu National Museum. Up until now, the oldest known extant document related to Japan-Vietnam relations was believed to be one from 1601, received by Tokugawa Ieyasu, and visible today at the National Archives of Japan Digital Archive – a document which, incidentally, I once wrote a paper on.
The Tokugawa-era document comes from Nguyen Hoang, lord of southern-central Vietnam1, who writes to Ieyasu reporting that he has captured the pirate Shirahama Kenki, who had terrorized the Vietnamese coast sixteen years earlier. Nguyen uses this occasion as a pretext for extending offers of good will, and requests for a continuation of good relations. Ieyasu’s response, which I have never seen as an image of an original document, but have only read descriptions of, describes the shuinjô (“red seals”) system, explaining that any Japanese seamen who do not carry licenses with the shogunate’s red seal can be apprehended as smugglers or pirates, but that those who do carry such licenses are licensed “above-board” merchants, authorized by the shogunate. Thus was the earliest known extant document recording, marking, the establishment or continuation of Japanese-Vietnamese relations – that is, until now.
The 1601 letter from Nguyen Hoang to Tokugawa Ieyasu, from the Gaiban Shokan.
The newly discovered Hideyoshi-era document is on display at the Kyushu National Museum in Dazaifu (Fukuoka prefecture) as part of a Vietnam exhibition which opened April 16.
In this document, a Lord Nguyen (presumably the same Nguyen Hoang, r. 1558-1613) writes, in Classical Chinese of course, something to the effect of “I offer gifts, and would like to bind us in friendly relations.” The document is dated with a Vietnamese reign era which corresponds with 1591 on the Western calendar, and is explicitly marked 「日本国・国王」 (“Country of Japan, King”). It seems to have been brought to Japan by a Japanese merchant, many of whom were actively engaged in maritime trade in Southeast Asia at the time. The primary figure active in Japan at that time for whom the title “King of Japan” would correspond would have been Toyotomi Hideyoshi; however, whether the Vietnamese were aware of Hideyoshi, or knew specifically who they were writing to, is unclear.
1) Generally known as Quang Nam 広南 or Cochinchina, in contrast to Tonking 東京 to the north, ruled by the Trinh family, and Champa, the territory of the Cham people to the south.