A letter of gratitude sent by 16th-century samurai general Toyotomi Hideyoshi has been found, evidence that his subordinate played a key role in saving the warlord's wife and mother during a coup attempt against his master, Oda Nobunaga.
A descendant of the subordinate, Hirose Hyogonosuke, donated the long-lost original letter to the Nagahama Castle Historical Museum here in September. The document, bearing the signature of Hideyoshi (1536-1598), has been confirmed to be authentic through a museum appraisal.
The letter, measuring 48.6 centimeters wide and 17.1 cm long, reads, “I am glad that you put a lot of efforts (in protecting my family members).”
Tetsuo Owada, professor emeritus at Shizuoka University and expert on feudal history, said, “It has become certain that Hyogonosuke was involved” in protecting Hideyoshi's wife and mother after the 1582 coup, in which feudal lord Nobunaga (1534-1582) was forced to kill himself during an attack by his vassal Akechi Mitsuhide (1528-1582).
Owada said the letter is valuable historical material for researchers on Hideyoshi’s career.
Hideyoshi, then a subordinate of Nobunaga and known as Hashiba Hideyoshi, was away from his Nagahama Castle here and was attacking Bicchu-Takamatsu Castle in present-day Okayama as a commander to conquer the Chugoku region.
On June 2, 1582, when Nobunaga was staying in Honnoji temple in Kyoto, troops led by Mitsuhide attacked him, leading him to commit suicide there. It is known as “Honnoji no Hen” (Honnoji temple incident).
There was a possibility that Mitsuhide’s troops would also attack Nagahama Castle, where Hideyoshi's wife, One, and his mother, Naka, resided at the time. To deal with the potential danger, the two fled with One’s elder brother.
Hyogonosuke protected them in his house in the village of Hirose in Mino province (current Ibigawa town of Gifu Prefecture), according to records.
Mitsuhide’s troops later occupied Nagahama Castle, but Hideyoshi defeated those troops on June 13, 1582, in Yamazaki of Yamashiro province (current Oyamazaki of Kyoto Prefecture).
One and others were able to return to Nagahama Castle six days later.
On the same day, June 19, Hideyoshi wrote the letter of appreciation to Hyogonosuke.
In the letter, as a reward, Hideyoshi said he would grant Hyogonosuke 500 koku of rice field areas in current Nagahama and Maibara of Shiga Prefecture. One koku equals the amount of rice one adult eats in a year.
The document's whereabouts was unknown for many years. It was found in the possession of a male descendant of Hyogonosuke, who is currently living in Tokyo.
The appraisal by the museum found that the “kao” signature written on the letter matched that of Hideyoshi.
The letter will be exhibited at the museum from Nov. 11 to Nov. 30. Admission is 400 yen (about $3.30) for high school students and older and 200 yen for elementary school and junior high school students.