Emperor Seimu (成務天皇)
Emperor Seimu (84 – July 29, 190) was the 13th emperor (reigned from February 18, 131 to July 29, 190) written in the "Kojiki" (The Records of Ancient Matters) and the "Nihonshoki" (Chronicles of Japan). His Japanese-style posthumous name was Wakatarashihiko no mikoto or Wakatarashihiko no sumera mikoto (in Kojiki).
The title 'Tarashihiko' was used for the 12th Emperor Keiko, the 13th Emperor Seimu, the 14th Emperor Chuai, and after an interval, the 34th Emperor Jomei and the 35th Empress Kogyoku who surely existed in the early seventh century also had the same title. That means the title of Tarashihiko originated in the early seventh century and the titles of the 12th, 13th and 14th were made in later days, and therefore, the existence of the Emperor Seimu is being questioned.
The description of the Emperor Seimu in Kyuji (mythical tradition) of the "Kojiki and Nihonshoki" is far less than that of the other emperors, therefore, his historical existence is being suspected, but if he did exist, it might have been in the middle of the fourth century.
Imperial palace
His palace was Shiga no Takaanaho no miya (currently, at Anou, Otsu City, Shiga Prefecture).
The "Kojiki" says 'Wakatarashihiko no sumera mikoto ruled the world residing at the palace of Takaanaho at Shiga in Omi Province.'
For those who see the Emperor Seimu as fictitious, the palace was a creation reflecting the Omi no miya Palace of the Emperor Tenji as a model.
Achievements
He was formally installed as Crown Prince in 121 and was enthroned in February, 131. He appointed TAKENOUCHI no Sukune as minister in 133. In September 135, he issued an imperial ordinance and established Kuni Kori and Agata Mura as administrative districts, and then he appointed Kuni no miyatsuko (provincial governor) and Inagi (regional official responsible for rice storage) for each district, drew boundaries at mountains and rivers between provinces, and laid down Mura (village) along Senpaku (roads) to develop local bureaucratic system in ancient Japan. It is said that people there lived in stability with complete peace of mind.
These descriptions are almost the same with those in the "Kojiki," that goes 'making TAKENOUCHI no Sukune a minister, he appointed Kuni no miyatsuko for small and large provinces, and defined boundaries between provinces and designated Agatanushi (territorial ruler) for small and large territories.'
It is worth noting that the half of Kuni no miyatsuko in the 'Kokuzohongi' (the original record of provincial governors) of the "Sendai Kujihongi" (Ancient Japanese History) was said to have been established under the reign of the Emperor Seimu. He installed his nephew, Tarashinakatsuhiko no mikoto (Emperor Chuai) as Crown Prince and passed away in July, 190 at the age of 107. The "Kojiki" says he was 95 years old then.
Imperial mausoleum
According to Shoryoryo (the Bureau for managing imperial mausoleums) of the "Engishiki" (an ancient book for codes and procedures on national rites and prayers), he was buried in Sakinotatanami no ikeshiri no misasagi. It is referred to as 'Sakinotatanami no misasagi' in the "Nihonshoki" and 'Sakinotatanami' in the "Kojiki." The mausoleum is now identified as Sakiishizukayama-kofun Tumulus (218-meter-long keyhole-shaped burial mound) in Misasagi-cho, Nara City, Nara Prefecture. It is said that this tumulus was robbed several times by the Edo period and the culprits were exiled or crucified.