Stories of the Japanese 01245 [Muromachi Period/Yoshimitsu Era] The Longest Pre-Modern Era Name: 'Oei'

Around this time, the relationship between the Shogunate and the former Southern Court (Daikakuji-to) seems to have deteriorated. Following the news of the unification of the Northern and Southern Courts, key figures of the Southern Court in Kyushu, such as Kikuchi Taketomo and Aso Koretake, surrendered to the Shogunate in October of the 4th year of Meitoku (1393). However, Prince Yoshiyari did not follow this reconciliation and continued his activities using the Southern Court's era name. Nevertheless, as it was merely a small-scale regime holed up in Yabe (Yame City, Fukuoka Prefecture), even the year and place of his death remain unclear.
On February 6th of the 5th year of Meitoku (1394), the Retired Emperor Gokameyama and Yoshimitsu met at Tenryu-ji Temple for consultations, and as a result, a decision was made on February 23rd to grant the Retired Emperor Gokameyama the title of 'Daijo Tenno' (Grand Retired Emperor). Normally, a member of the imperial family who has experienced being Emperor becomes a 'Daijo Tenno' (Retired Emperor), so this could be considered a clerical error. However, some historians believe that the kanji were intentionally changed to treat the Retired Emperor Gokameyama differently from a standard retired emperor, essentially 'denying that he was ever an Emperor.' If that were the case, it must have caused quite a controversy at the time.
Yoshimitsu, having gained the power to control even the Imperial Court, began to control the era names as well. On July 1st of the 5th year of Meitoku (1394), when the Confucian scholar Higashibojo Hidenaga (1338–1411) visited Yoshimitsu to present proposals for a new era name, Yoshimitsu suggested:
'The Ming era name "Hongwu" has lasted for over 20 years and is considered auspicious. Why not include the character "Hong"?'
Although Hidenaga was inwardly opposed to this, he submitted three proposals—"Hongde," "Hongye," and "Honghua"—to Yoshimitsu that same day, and it is said that Yoshimitsu happily chose "Hongde."
However, in the evening, when Hidenaga reported the situation to the Minister of the Left, Ichijo Tsunetsugu, Tsunetsugu opposed imitating a foreign era name. The details of their exchange are recorded in Tsunetsugu's diary.
Tsunetsugu: 'Why on earth did you recommend such a strange era name?'
Hidenaga: 'The reason the Muromachi-dono is obsessed with the character "Hong" is simply because it is an era name currently in use in a foreign country. I suppose some monk from the Gozan temples put the idea in his head that we should learn from Ming culture. It was a strict order, so I had no choice but to propose it.'
Tsunetsugu: 'The world is coming to an end. This is what it means to fawn over power. Why must our country adopt the ways of a foreign land? Besides, the character "Hong" is associated with "floods," so it is ominous. There is a risk it could invite water disasters.'
Having received opposition from the Minister of the Left, Yoshimitsu gave up and withdrew "Hongde," deciding to go with "Oei" instead. It was rare for Yoshimitsu to withdraw his own proposal after receiving opposition from the court nobles.
However, the price for rejecting Yoshimitsu's wishes was high. Afterward, every time the Imperial Court requested a change of the era name, Yoshimitsu rejected them all, and this attitude continued through the time of his son, Yoshimochi.
As a result, Oei lasted for 35 years, becoming the longest-running era name in history, excluding the period after the Meiji era when the 'one reign, one era name' system was established.