Soga clan (蘇我氏 Soga uji ) 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 (Ō-omi) and was the first of many families to dominate the Imperial House of Japan by influencing the order of succession and government policy. In fact, the last Soga predates any historical work in Japan, and very little is known about the earliest members.
 Soga no Iname
Soga no Iname served as Great Minister from 536 until his death in 570, and was the first of the Soga clan to carry to extreme lengths the domination of the Throne by the nobility. One of the chief ways he exerted influence through was marital connections with the imperial family; Iname married two of his daughters to Emperor Kimmei, one giving offspring to an Emperor, Emperor Yomei. The next five emperors all had a wife or mother who was a descendant of Iname. In this way the Soga unified and strengthened the country by expanding the power of the Emperor as a symbol and spiritual leader as they took control of secular matters.
 Connection to Buddhism and Korea
Having close ties with the Baekje and Goguryeo of Korea, the Soga clan supported the spread of Buddhism when it was first introduced in Japan during the 6th century by monks from the Korean kingdom of Baekje. Many Japanese at the time, disliking foreign ideas and believing that this new religion might be an affront to the traditional "kami", or Shinto gods, opposed Buddhism. The rival Mononobe and Nakatomi clans succeeded in gathering hostility against this new religion when a disease spread, following the arrival of a Buddhist statue. It was claimed the epidemic was a sign of anger by the local spirits and the Soga temple at the palace was burned down.
The Soga family, however, firmly believed that the most civilized people believed in Buddhism and continued to actively promote it, placing a holy image of the Buddha in a major Shinto shrine. Soga no Iname claimed that Buddhism brought with it a new form of government that would subvert the independence of the clans, unifying the Japanese people under the emperor. After fifty years of ideological war, Buddhism, defended and protected by the Soga, began to take hold in Japan.
 Political assertiveness and reactions
However, by 644, the heads of the Soga clan were no longer satisfied to act behind the scenes. Soga no Emishi and his son Iruka began to build more and more elaborate palaces and tombs for themselves, styling themselves sovereigns. There seems little doubt that they intended to do away with the reigning dynasty, making themselves the new imperial line. But the leader of the Nakatomi clan, Nakatomi no Kamatari, conspired with Soga no Kurayamada no Ishikawa no Maro and Prince Naka no Ōe, and arranged for Iruka's assassination. Emishi's followers dispersed, and many were subsequently killed. The Soga clan's hold over the imperial family was broken and, two years later, Emperor Kōtoku enacted the Taika Reforms returning power to the emperor.
- Sansom, George (1958). A History of Japan to 1334' Stanford, California: Stanford University Press.
- Hall, John Whitney, et al. (1993). The Cambridge History of Japan: Volume 1 Ancient Japan. Cambridge University Press. ISBN 0-521-22352-0.