Minamoto clan in the context of "Genpei War"

The Kamakura period (鎌倉時代, Kamakura jidai; 1185–1333) is a period of Japanese history that marks the governance by the Kamakura shogunate, officially established in 1192 in Kamakura by the first shōgun Minamoto no Yoritomo after the conclusion of the Genpei War, which saw the struggle between the Taira and Minamoto clans. The period is known for the emergence of the samurai, the warrior caste, and for the establishment of feudalism in Japan.

There are various theories as to the year in which the Kamakura period and Kamakura shogunate began. In the past, the most popular theory was that the year was 1192, when Minamoto no Yoritomo was appointed Seii Taishōgun (征夷大将軍). Later, the prevailing theory was that the year was 1185, when Yoritomo established the Shugo (守護), which controlled military and police power in various regions, and the Jitō (地頭), which was in charge of tax collection and land administration. Japanese history textbooks as of 2016 do not specify a specific year for the beginning of the Kamakura period, as there are various theories about the year the Kamakura shogunate was established.

The Taira (平; Japanese pronunciation: [taꜜi.ɾa]) was one of the four most important clans that dominated Japanese politics during the Heian period of Japanese history – the others being the Minamoto, the Fujiwara, and the Tachibana. The clan is divided into four major groups, named after the emperors they descended from: Kanmu Heishi, Ninmyō Heishi, Montoku Heishi, and Kōkō Heishi, the most influential of which was the Kanmu Heishi line.

In the twilight of the Heian period, the Taira controlled the boy emperor Antoku (himself the grandson of the powerful Kugyō Taira no Kiyomori) and had effectively dominated the Imperial capital of Heian. However, they were opposed by their rivals the Minamoto clan (the Genji), which culminated in the Genpei War (1180–1185 AD). The five-year-long war concluded with a decisive Taira defeat in the naval Battle of Dan-no-Ura, which resulted in the deaths of Antoku and Taira leaders. Following the war, the victorious Minamoto established Japan's first shogunate in Kamakura. The name "Genpei" comes from alternate readings of the kanji "Minamoto" (源 Gen) and "Taira" (平 Hei).

The Kamakura shogunate (Japanese: 鎌倉幕府, Hepburn: Kamakura bakufu) was the feudal military government of Japan during the Kamakura period from 1185 to 1333.

The Kamakura shogunate was established by Minamoto no Yoritomo after victory in the Genpei War and appointing himself as shōgun. Yoritomo governed Japan as military dictator from the eastern city of Kamakura with the emperor of Japan and his Imperial Court in the official capital city of Heian-kyō (Kyoto) as figureheads. The Kamakura shōguns were members of the Minamoto clan until 1226, the Fujiwara clan until 1252, and the last six were minor princes of the imperial family. The Hōjō clan were the de facto rulers of Japan as shikken (regent) of the shōgun from 1203. The Kamakura shogunate saw the Jōkyū War in 1221 and the Mongol invasions of Japan under Kublai Khan in 1274 and 1281. The Kamakura shogunate was overthrown in the Kenmu Restoration under Emperor Go-Daigo in 1333, re-establishing Imperial rule until Ashikaga Takauji and his offspring overthrew the imperial government and founded the Ashikaga shogunate in 1336 (Nanboku-chō period).

The Hosokawa clan (細川氏, Hosokawa-shi; Japanese pronunciation: [ho.so.ka.wa(ꜜ.ɕi), -soꜜ.ka.wa(.ɕi)]) is a Japanese samurai kin group or clan. The clan descends from the Seiwa Genji, a branch of the Minamoto clan, and ultimately from Emperor Seiwa, through the Ashikaga clan. It produced many prominent officials in the Ashikaga shogunate's administration. In the Edo period, the clan was one of the largest landholding daimyo families in Japan. The current clan head Morihiro Hosokawa served as Prime Minister of Japan.

Minamoto no Yoritomo (源 頼朝; Japanese pronunciation: [mʲi.na.mo.to no (|) jo.ɾʲi.to.mo], May 9, 1147 – February 9, 1199) was the founder and the first shogun of the Kamakura shogunate, ruling from 1192 until 1199, also the first shogun in the history of Japan to hold de-facto power over Japan. He was married to Hōjō Masako, who acted as regent (shikken) after his death.

Yoritomo was the son of Minamoto no Yoshitomo and belonged to Seiwa Genji's prestigious Kawachi Genji family. After successfully maneuvering himself to the position of rightful heir of the Minamoto clan, he led his clan against the Taira from his capital in Kamakura, beginning the Genpei War in 1180. After five years of civil war, the Minamoto clan finally defeated the Taira in the Battle of Dan-no-ura in 1185. Yoritomo established the supremacy of the samurai caste and the first shogunate (bakufu) which was to be centered around Kamakura, thus beginning the feudal age in Japan, which lasted until the 17th century.

The Tokugawa clan (徳川氏, Tokugawa-shi, Tokugawa-uji; Japanese pronunciation: [to.kɯꜜ.ɡa.wa, -ŋa.wa, -kɯ.ɡa.waꜜ.ɕi, -ŋa.waꜜ-]) is a Japanese dynasty which produced the Tokugawa shoguns who ruled Japan from 1603 to 1868 during the Edo period. It was formerly a powerful daimyō family. They nominally descended from Emperor Seiwa (850–880) and were a branch of the Minamoto clan (Seiwa Genji) through the Matsudaira clan. The early history of the clan remains a mystery. Nominally, the Matsudaira clan is said to be descended from the Nitta clan, a branch of the Minamoto clan, but this is considered to be untrue or unlikely.

The Matsudaira clan (松平氏, Matsudaira-shi) was a Japanese samurai clan that descended from the Minamoto clan. It originated in and took its name from Matsudaira village, in Mikawa Province (modern-day Aichi Prefecture). During the Sengoku period, the chieftain of the main line of the Matsudaira clan, Matsudaira Motoyasu became a powerful regional daimyo under Oda Nobunaga and Toyotomi Hideyoshi and changed his name to Tokugawa Ieyasu. He subsequently seized power as the first shōgun of the Tokugawa shogunate which ruled Japan during the Edo period until the Meiji Restoration of 1868. Under the Tokugawa shogunate, many cadet branches of the clan retained the Matsudaira surname, and numerous new branches were formed in the decades after Ieyasu. Some of those branches were also of daimyō status.

After the Meiji Restoration and the abolition of the han system, the Tokugawa and Matsudaira clans became part of the new kazoku nobility.