Uda Tennō (宇多天皇?) (June 10, 867 - September 3, 931) was the 59th emperor of Japan, according to the traditional order of succession.
He reigned from 887 to 897. Prior to his ascension to the Chrysanthemum Throne, his personal name (imina) was Imperial Prince Sadami (Sadami-shinnō).
He was the third son of Kōkō Tennō. His mother was Empress Dowager Hanshi, daughter of Imperial Prince Nakano (who was the son of Emperor Kanmu).
She had five imperial consorts and 20 children. Among her children were Imperial Prince Atsumi and Imperial Prince Atsuzane.
In Ancient Japan, there were four noble clans, the Gempeitōkitsu (源平藤橘). One of these clans was the Minamoto or Genji clan. Some grandchildren of Emperor Uda were given the Minamoto surname; this surname is the most commonly used surname for the ancient nobles.
But to differentiate the descendants of Uda from the other branches of the Minamoto family, that branch was called as Uda Genji (宇多源氏). Some of the Uda Genji moved to the province of Ōmi, and were known as Ōmi Genji (近江源氏).
Among the Uda Genji was Minamoto no Masanobu, a son of the Imperial Prince Atsuzane, and was a courtier. He became Sadaijin (Minister of the Left). One of Masanobu's daughters, Minamoto no Rinshi, married Fujiwara no Michinaga and from that relationship they had three Empress Dowagers and two sesshō as children.
Among Masanobu's descendants, several noble clans or kuge such as the Niwata, Ayanokōji, Itsutsuji, Ōhara and Jikōji arose.
From his fourth son, Sukeyoshi, the Sasaki clan was born and from this clan, the Kyōgoku clan. These descendants are currently called as Ōmi Genji. From this branch, Sasaki Takauji was one of the allies in the Ashikaga shogunate and the Amako clan was created from his brother.
Imperial Prince Sadami's father, Kōkō Tennō, demoted his sons from the rank of Imperial Princes in order to reduce his political influence and ensure control of the country. Thus the prince assumed the surname Minamoto and named himself Minamoto no Sadami.
In 887, Kōkō Tennō was concerned about having a successor, so Sadami was promoted to Imperial Prince, with the support of the kampaku Fujiwara no Mototsune, because Sadami had been adopted by a half-sister of Mototsune.
At the end of the same year, the emperor died and the Imperial Prince Sadami assumed the throne at the age of 20, with the name of Emperor Uda. The new emperor asked Mototsune to assist him as kanpaku, even though he was old enough to rule, he felt limited and that if he refused his help, he would abdicate as emperor.
In 888, the construction of the Buddhist temple of Ninna-ji, which would be his new home after his abdication, was completed.
After Mototsune's death in 891, other courtiers assisted the emperor, such as Fujiwara no Tokihira and Sugawara no Michizane.
The latter persuades the emperor not to send any more ambassadors to China, a tradition performed by all emperors until his reign.
During his reign, the Kamo Shrine Festival is held for the first time. In 897 he abdicates at the age of 30, in favor of his son Daigo Tennō.
Later in 900, he enters the Buddhist temple of Ninna-ji and assumes the name Kongō Kaku. He was called "the Cloistered Emperor of Teiji," after the name of the hall where he resided after his conversion to a monk.
Kongō Kaku died in 931, at the age of 65. He was buried in the "Seven Imperial Tombs" at Ryōan-ji, Kyoto.
The burial mound dedicated to Emperor Uda is known as O-uchiyama; and the tomb was made through a restoration of imperial tombs in the late 19th century by the Meiji Emperor.
Kugyō (公卿) is the collective term for the most powerful personages directly linked to the service of the emperor of pre-Meiji Restoration Japan.
They were hereditary courtiers whose experience and prestige had brought them to the top of the courtly ladder.