Emperor Uda was the third son of Emperor Kōkō. His mother was Empress Dowager Hanshi, a daughter of Prince Nakano (who was himself a son of Emperor Kanmu). Uda had five Imperial consorts and 20 Imperial children. Particularly important sons include:
In ancient Japan, there were four noble clans, the Gempeitōkitsu (源平藤橘). One of these clans, the Minamoto clan (源氏), is also known as Genji. Some of Uda's grandchildren were granted the surname Minamoto (Minamoto is the most used surname for former Japanese royalty.). In order to distinguish Uda's descendants from other Minamoto clan families (源氏) or Genji, they became known as the Uda Genji (宇多源氏). Some of the Uda Genji moved to Ōmi Province and known as Sasaki clan (佐々木氏) or Ōmi Genji (近江源氏).
Among the Uda Genji, Minamoto no Masazane (源雅信), a son of Prince Atsumi (敦実親王) succeeded in the court. Masazane became sadaijin (Minister of the Left). One of Masazane's daughters, Minamoto no Rinshi (源倫子) married Fujiwara no Michinaga and from this marriage three empresses dowagers and two regents (sesshō) were born.
From Masanobu, several kuge families originated including the Niwata, Ayanokōji, Itsutsuji, Ōhara and Jikōji. From his fourth son Sukeyosi, the Sasaki clan originated, and thus Kyōgoku clan originated. These descendants are known as Ōmi Genji today. From this line, Sasaki Takauji made a success at the Muromachi shogunate and the Amago clan originated from his brother.
Uda's father, Emperor Kōkō, demoted his sons from the rank of imperial royals to that of subjects in order to reduce the state expenses, as well as their political influence. Sadami was given the clan name of Minamoto and named Minamoto no Sadami. Later, in 887, when Kōkō needed to appoint his successor, Sadami was once again promoted to the Imperial Prince rank with support of kampaku Fujiwara no Mototsune, since Sadami was adopted by a half-sister of Mototsune. After the death of his father in November of that year, Sadami-shinnō ascended to the throne.
In the beginning of Uda's reign, Mototsune held the office of kampaku (or chancellor). Emperor Uda's reign is marked by a prolonged struggle to reassert power by the Imperial Family away from the increasing influence of the Fujiwara, beginning with the death of Mototsune in 891. Records show that shortly thereafter, Emperor Uda assigned scholars Sukeyo and Kiyoyuki, supporters of Mototsune, to provincial posts in the remote provinces of Mutsu and Higo respectively. Meanwhile, non-Fujiwara officials mainly from the Minamoto family were promoted to prominent ranks, while his trusted counselor, Sugawara no Michizane rapidly rose in rank within five years to reach the third rank in the court, and supervision of the Crown Prince's household. Meanwhile, Mototsune's son and heir, Fujiwara no Tokihira, rose in rank, but only just enough to prevent an open power struggle.
Meanwhile, Emperor Uda attempted to return Court politics to the original spirit envisioned in the Ritsuryō Codes, while reviving intellectual interest in Confucian doctrine and culture. In the seventh month of 896, Emperor Uda dispatched Sugawara no Michizane to review prisoners in the capitol and provide a general amnesty for the wrongfully accused, in keeping with Chinese practices. Emperor Uda also issued edicts reinforcing peasant land rights from encroachment by powerful families in the capital or monastic institutions, while auditing tax collections made in the provinces.
When determining promotions and rewards for palace guards who have been on duty long hours and have good reputations, do not hold rigidly to precedents; just avoid the words of women and the advice of lesser men ... When foreign [literally "barbarian"] guests must be received, greet them from behind a curtain; do not face upon them directly. I have already made an error with Li Huan [a Chinese summoned to court in 896] ... Do not select as provincial officials those who request appointment. Only allow to serve those who have experience in the various offices and are known to be effective.
In 897, Uda abdicated in favor of his eldest son, Prince Atsuhito, who would later come to be known as Emperor Daigo. Uda left behind an hortatory will or testament which offered general admonitions or precepts for his son's guidance (see excerpt at right). The document praises Fujiwara no Tokihira as an advisor but cautions against his womanizing; and Sugawara no Michizane is praised as Uda's mentor. Both were assigned by Emperor Uda to look after his son until the latter reach maturity.
His Buddhist name was Kongō Kaku. He was sometimes called "the Cloistered Emperor of Teiji(亭子の帝)," because the name of the Buddhist hall where he resided after becoming a priest was called Teijiin.
The former emperor is buried amongst the "Seven Imperial Tombs" at Ryōan-ji Temple in Kyoto. The mound which commemorates the Hosokawa Emperor Uda is today named O-uchiyama. The emperor's burial place would have been quite humble in the period after Uda died. These tombs reached their present state as a result of the 19th century restoration of imperial sepulchers which were ordered by Emperor Meiji.
In general, this elite group included only three to four men at a time. These were hereditary courtiers whose experience and background would have brought them to the pinnacle of a life's career.
Consort (Nyōgo): Tachibana no Yoshiko/Gishi (橘義子), Tachibana no Hiromi’s daughter
Court Attendant (Koui): Minamoto no Sadako (源貞子), Minamoto no Noboru’s daughter
Court Attendant (Koui): Princess Norihime (徳姫女王), Prince Tōyo’s daughter
Court Attendant (Koui): Fujiwara no Yasuko (藤原保子), Fujiwara no Arizane’s daughter
Lady-in-waiting: Fujiwara no Hōshi (藤原褒子), Fujiwara no Tokihira’s daughter
Court lady: A daughter of Fujiwara no Tsugukage, Ise (伊勢; 875/7–ca. 939)