Japan

Japan's imperial line was founded when a tribal band from Kyushu migrated to Honshu and took control of territory there. These new arrivals worshipped the sun goddess Amaterasu.

The 'Japanese Historical Era' starts in 6 60 BC (AD 1999 + 660 = 2659 Anno Japoniae).

In modern times the Japanese historical era, unlike the Chinese, has frequently been used for ordinary dating. This resulted in the famous naval fighter aircraft of the Second World War, the Mitsubishi A6M, being known as the 'Zero' for the year in which it became operational, 2600 of the Jimmu Era (AD 1940 to the western world).

The era is now less frequently used in terms of dating, in part because of unpleasant associations with Japanese totalitarianism.

All imperial names are known right from the start, but not necessarily their dates.

Jimmu Tenno, founder figure of modern Japan, as seen in a coloured wood engraving by Nakai Tokujiro in 1908 during the country's growing imperial status in the twentieth century

Heian Period

Where three dates are given in this period, the second represents the emperor's official retirement (or, later, that of the shogun or regent). This came to be a device by which Fujiwara ministers, starting with the regent (sessho), Fujiwara Yoshifusa (858-872), could exercise control over minor emperors.

As Fujiwara power declined, retired emperors, who had become monks, began to exercise influence from their monasteries. This became the institution of the 'Cloistered Emperors'. Such emperors were known by the title 'In', producing names such as Shirakawa-In, who was the first to assume authority in this way, in 1086.

The main king list (see sidebar links) gives the names of cloistered emperors and the dates of their assumption of cloistered power. Usually this is identical to the dates for their retirement, but sometimes there was a delay between retirement and the assumption of cloistered power (such as with Emperor Toba who reigned in 1107-1123, but only became a cloistered emperor in 1129). There may also be a second retirement date.

Go-Toba (or Toba II) was the last effective cloistered emperor. His second retirement was forced after his abortive attack on the Hojo regent, Yoshitoki in 1221, the attack being known as the Jokyu War. He was exiled for the rest of his life to the remote Oki Islands where, amongst other things, he worked on forging a sword, a growing and already notable mastered art form.

The Heian period in Japan witnessed the solidification of the process of imperial rule over an increasingly unified Japan, while also enabling the rise of the shoguns and the ending in the ninth century of close ties with China which allowed Japanese internal culture to fully emerge

Rebellion

This sword was to replace that of the imperial regalia which had been lost at sea along with the child Emperor Antoku, during the Battle of Dan-no-ura (see below). Go-Toba also intended to use it to kill the Hojo clan leaders, something he never achieved.

Later in Japanese history it became common for many figures, regents and shoguns as well as emperors, to retire from office but sometimes to continue exercising much of their previous power from behind the scenes.

A dramatic exception to that practice was when Emperor Go-Daigo refused to accept retirement in 1331. Instead, he organised a rebellion against the Hojos and succeeded in overthrowing them in 1333. However, he was then betrayed in 1336 by the Ashikagas who, like the Hojos, installed their own counter-emperor.

Go-Daigo and three successors were able to hold out in Yoshino and elsewhere against the Ashikagas until 1392. Although Go-Daigo's line was then accepted as legitimate, it was the Ashikaga counter-emperor who was installed (Go-Komatsu), and an agreement to alternate between the two lines was never honoured.

The eleventh century saw the rise of the Minamoto and Taira clans, whose internecine early samurai-period conflict would become part of the stuff of legend

End of the Tairas

The Heian Period ends with the naval battle of Dan-no-ura in 1185. The Taira (or Heike) clan had dominated the imperial court under Kiyomori (1118-1181), but the Minamoto (or Genji) clan overwhelmed them after his death.

The leader of the Minamoto clan was Yoritomo (1147-1199), who became the first Kamakura shogun, but it was his brother, Yoshitsune (1159-1189), who commanded the Minamoto forces and who destroyed the Taira at the aforementioned Battle of Dan-no-ura.

The battle ended with one of the most dramatic and poignant moments in world history. Kiyomori's widow, Nii-no-ama, with her grandson, the seven-year-old Emperor Antoku, decided to leap into the sea, carrying the imperial regalia with them rather than be taken by their enemies.

The scene is recounted in the epic Heike-Monogatari, and is hauntingly portrayed in Masaki Kobayashi's feature film, Shin Heike Monogatari (1964).

Text copyright © P L Kessler. An original feature for the History Files.