Shōhei

Overview

Shōhei (正平) was a Japanese era name (年號, nengō, literally "year name") used by the Southern Court during the Era of Northern and Southern Courts. The era began in December 1346 and lasted until July 1370, following the Kōkoku era and preceding the Kentoku era. It falls within the Muromachi period (1336–1573), a time when two rival imperial lines claimed the throne.

During Shōhei, the Southern Court, based in Yoshino, was led by Emperor Go-Murakami (後村上天皇, Go-Murakami-tennō) and later Emperor Chōkei (長慶天皇, Chōkei-tennō). In Kyoto, the Northern Court had its own emperors: Emperor Kōmyō (光明天皇, Kōmyō-tennō), Emperor Sukō (崇光天皇, Sukō-tennō), and Emperor Go-Kōgon (後光嚴天皇, Go-Kōgon-tennō). The era name Shōhei was proclaimed by the Southern Court, and the Northern Court used a different set of era names during the same years.

What Defined the Era

The Shōhei era was defined by the ongoing conflict between the Southern and Northern Courts, a split that began in 1336 when Ashikaga Takauji established a rival emperor in Kyoto. The Southern Court, holding the imperial regalia, considered itself the legitimate line. The era name itself was a political statement: by issuing a nengō, the Southern Court asserted its authority to mark time, a privilege traditionally reserved for the true sovereign.

The era's length—nearly twenty-five years—reflects a period of sustained military and political struggle. The Southern Court, though poorer and more isolated in Yoshino, mounted repeated campaigns to retake Kyoto. The Northern Court, backed by the Ashikaga shogunate, controlled the capital and most of central Japan. Neither side could achieve a decisive victory during Shōhei, and the conflict settled into a grinding stalemate punctuated by battles, sieges, and shifting allegiances among regional warlords.

Key Events

In 1348, early in the Shōhei era, the Northern Court's forces under Kō no Moronao and Kō no Moroyasu captured Yoshino, forcing Emperor Go-Murakami to flee to a more remote location. The Southern Court lost its base but continued resistance from the mountains of Yamato Province.

In 1351, the Ashikaga shogunate suffered internal strife when Takauji's brother Tadayoshi rebelled against him. Takauji temporarily sided with the Southern Court, and for a brief period the Southern Court regained control of Kyoto. This reconciliation did not last; Tadayoshi died in 1352, and Takauji himself died in 1358, leaving the shogunate to his son Yoshiakira.

In 1352, the Southern Court launched a major offensive and seized Kyoto for several months. Emperor Go-Murakami entered the capital, but Northern Court forces recaptured the city before the year ended. Similar attempts in 1353 and 1354 also failed to hold Kyoto for long.

In 1368, Emperor Go-Murakami died, and Emperor Chōkei succeeded to the Southern throne. The era name Shōhei continued under Chōkei until July 1370, when it was replaced by Kentoku. The change came as the Southern Court's military position weakened and its remaining strongholds came under increasing pressure from the shogunate.

The Name in Japanese

The era name is written 正平 in kanji. Its kana reading is しょうへい, and its romaji is Shōhei.

The name breaks down character by character as follows:

• 正 (しょう, shō): meaning "correct," "right," or "proper." This character carries connotations of justice, legitimacy, and setting things straight. It appears in words like 正しい (ただしい, tadashii, "correct") and 正義 (せいぎ, seigi, "justice").

• 平 (へい, hei): meaning "peace," "flat," or "level." This character evokes calm, stability, and the absence of conflict. It appears in words like 平和 (へいわ, heiwa, "peace") and 平等 (びょうどう, byōdō, "equality").

Together, 正平 reads as "righteous peace" or "proper tranquility." The name expresses a hope for a return to correct order and peaceful rule—an aspiration that, given the era's long civil war, remained unfulfilled. The choice of these two characters was deliberate: the Southern Court claimed to be the rightful line, and the name asserted that its victory would bring both justice and peace to the realm.

How the Era Name Works

A Japanese era name, or nengō (年號), is a system for counting years that originated in China and was adopted in Japan in 645 CE. Each era name is chosen by the reigning emperor and remains in effect until the emperor abdicates, dies, or decides to change it for auspicious or political reasons. When an era name changes, the calendar resets to year one of the new era.

During the Era of Northern and Southern Courts (1336–1392), two emperors reigned simultaneously, each with his own court and his own nengō. The Southern Court in Yoshino and the Northern Court in Kyoto each issued era names, so the same calendar years carried different names depending on which court one recognized. Shōhei was the Southern Court's name for the period from December 1346 to July 1370; the Northern Court used its own era names, such as Jōwa and Kan'ō, during the same span.

The nengō system continued in use until 1868, when the Meiji government adopted the one-emperor-one-era-name rule (一世一元, issei-ichigen). Under this rule, each emperor's reign has a single era name, and the era name ends only at the emperor's death. The modern era names—Meiji, Taishō, Shōwa, Heisei, and Reiwa—follow this system. In historical writing, nengō remain essential for dating events precisely, since Japanese records before 1868 typically refer to years by era name and year number rather than by the Western calendar.