was an ancient Japanese

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 hereditary title denoting rank and political standing (a kabane

Kabane

were hereditary titles used in ancient Japan to denote rank and political standing. There were more than thirty. Some of the more common kabane were omi, muraji, , , , , , and ....

) that, along with muraji

Muraji

Muraji . Muraji was an ancient Japanese hereditary title denoting rank and political standing that was reserved for the most powerful among the Tomo no Miyatsuko clans, which were clans associated with particular occupations...

, was reserved for the most powerful clans during the Kofun period

Kofun period

The is an era in the history of Japan from around 250 to 538. It follows the Yayoi period. The word kofun is Japanese for the type of burial mounds dating from this era. The Kofun and the subsequent Asuka periods are sometimes referred to collectively as the Yamato period...

. The omi clans generally took their names from the geographic location from which they originated, such as the Soga (蘇我), the Kazuraki (葛城), the Heguri (平群), the Kose (巨勢), the Kasuga

Kasuga

may mean* Kasuga, a city in Fukuoka Prefecture, Japan* Kasuga, a former town in Hyōgo Prefecture* Kasuga, a former village in Gifu Prefecture* Kasuga Shrine, a major Shinto shrine in Nara* Kasugayama Castle, the primary fortress of warlord Uesugi Kenshin...

 (春日) and the Izumo

Izumo

Izumo can refer to:* Izumo Province, one of the old provinces of Japan* Izumo, Shimane, a city in former Izumo province* Izumo-taisha, a famous Shinto shrine in Izumo city...

 (出雲). By tradition those who held the kabane of omi were considered branches of the imperial line (皇別氏族, kōbetsu shizoku), and they claimed that they were descendants of Emperor Kōgen

Emperor Kogen

, also known as Ooyamatonekohikokunikuru no Mikoto, was the eighth emperor of Japan, according to the traditional order of succession.No firm dates can be assigned to this emperor's life or reign, but he is conventionally considered to have reigned from 214 BC–158 BC.-Legendary narrative:Modern...

, although there is no historical evidence to support this.


The most powerful omi added the prefix Ō (大) to omi and was referred to as Ōomi (大臣). Examples of Ōomi mentioned in the Nihon Shoki

Nihon Shoki

The , sometimes translated as The Chronicles of Japan, is the second oldest book of classical Japanese history. It is more elaborate and detailed than the Kojiki, the oldest, and has proven to be an important tool for historians and archaeologists as it includes the most complete extant historical...

included Kazuraki no Tsubura (葛城円) during the reign of Emperor Richū

Emperor Richu

was the 17th emperor of Japan, according to the traditional order of succession.No firm dates can be assigned to this emperor's life or reign, but he is conventionally considered to have reigned from 400–405.-Legendary narrative :...

, Heguri no Matori (平群馬鳥) during the reign of Emperors Yūryaku

Emperor Yuryaku

was the 21st emperor of Japan, according to the traditional order of succession.Yūryaku is remembered as a patron of sericulture.No firm dates can be assigned to this emperor's life or reign, but he is conventionally considered to have reigned from 456–479....

 and Seinei

Emperor Seinei

was the 22nd emperor of Japan, according to the traditional order of succession.No firm dates can be assigned to this emperor's life or reign, but he is conventionally considered to have reigned from 480–484.-Legendary narrative:...

, Kose no Ohito (許勢男人) during the reign of Emperor Keitai

Emperor Keitai

, also known as Keitai-okimi, was the 26th emperor of Japan, according to the traditional order of succession.No firm dates can be assigned to this emperor's life or reign, but he is conventionally considered to have reigned from 507–531....

 and the four generations of Sogas

Soga clan

The was one of the most powerful clans in Yamato Japan and played a major role in the spread of Buddhism. For many generations, in the 5th and 7th centuries, the Soga monopolized the position of Great Royal Chieftain and was the first of many families to dominate the Imperial House of Japan by...

 who dominated the title during the 6th and 7th centuries: Soga no Iname

Soga no Iname

. Soga no Iname was a leader of the Soga clan and a statesman during the reign of Emperor Kimmei in the Asuka period. He was the first person to hold the position of Ōomi that can be verified with reasonable accuracy, in 536 AD...

, Soga no Umako

Soga no Umako

was the son of Soga no Iname and a member of the powerful Soga clan of Japan.Umako conducted political reforms with Prince Shōtoku during the rules of Emperor Bidatsu and Empress Suiko and established the Soga clan's stronghold in the government by having his daughter married with members of the...

, Soga no Emishi

Soga no Emishi

was a statesman of the Yamato Imperial Court. His alternative names include Emishi and Toyora no Ooomi . After the death of his father Soga no Umako, Emishi took over Ooomi, the Minister of state, from his father....

 and Soga no Iruka

Soga no Iruka

was a statesman in the Asuka Period of Japan.He was a son of Soga no Emishi. He was assassinated by Prince Naka-no-Ōe though he tried to murder Prince Yamashiro, and to rule the emperor family. Emishi also committed suicide soon after his son's death, and the main branch of the Soga clan went...

.


When the kabane system was reformed into the eight kabane

Kabane

were hereditary titles used in ancient Japan to denote rank and political standing. There were more than thirty. Some of the more common kabane were omi, muraji, , , , , , and ....

 system in 684

684

Year 684 was a leap year starting on Friday of the Julian calendar. The denomination 684 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Asia :* Wu Ze Tian takes power in China.* The Ummayad...

, the powerful omi of the time were given the kabane of ason

Ason

is a prestigious title , initially conferred in the Nara period of the history of Japan, on princes who had been reduced to the commonalty.Notable ason were:...

, which ranked second under the new system, and omi itself was dropped to sixth in rank.