{{Italic title, reason= :Japanese words and phrases ''Seishitsu'' (正室) is the

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

term of the

Edo period The or is the period between 1603 and 1867 in the history of Japan, when Japan was under the rule of the Tokugawa shogunate and the country's 300 regional '' daimyo''. Emerging from the chaos of the Sengoku period, the Edo period was characte ...

for the official

wife A wife (plural, : wives) is a female in a marital relationship. A woman who has separated from her partner continues to be a wife until the marriage is legally Dissolution (law), dissolved with a divorce judgement. On the death of her partner, ...

of high-ranking persons. The tennō, kugyō (court officials), ''

shōgun , officially , was the title of the military dictators of Japan during most of the period spanning from 1185 to 1868. Nominally appointed by the Emperor, shoguns were usually the de facto rulers of the country, though during part of the Kamak ...

'' and ''

daimyō were powerful Japanese magnates, feudal lords who, from the 10th century to the early Meiji period in the middle 19th century, ruled most of Japan from their vast, hereditary land holdings. They were subordinate to the shogun and nominal ...

s'' often had several wives to ensure the birth of an heir. The ''seishitsu'' had a status above other wives, called ''sokushitsu'' (側室,

concubine Concubinage is an interpersonal and sexual relationship between a man and a woman in which the couple does not want, or cannot enter into a full marriage. Concubinage and marriage are often regarded as similar but mutually exclusive. Concubi ...

). The system dates back to the

ritsuryō , , is the historical law system based on the philosophies of Confucianism and Chinese Legalism in Japan. The political system in accord to Ritsuryō is called "Ritsuryō-sei" (律令制). ''Kyaku'' (格) are amendments of Ritsuryō, ''Shiki'' ...

system in the

Nara The National Archives and Records Administration (NARA) is an " independent federal agency of the United States government within the executive branch", charged with the preservation and documentation of government and historical records. It ...

and

Heian period The is the last division of classical Japanese history, running from 794 to 1185. It followed the Nara period, beginning when the 50th emperor, Emperor Kanmu, moved the capital of Japan to Heian-kyō (modern Kyoto). means "peace" in Japanese ...

s. At the time, the main wife was called ''chakusai'' (嫡妻). The last Japanese emperor to have official concubines was Emperor Meiji. Succession disputes between sons of the official wife and concubines were a constant source of internal, often armed conflict within houses (

O-Ie Sōdō O-Ie Sōdō (, "house strife") were noble family disputes within the samurai and aristocratic classes of Japan, particularly during the early Edo period (17th century). The most famous is the '' Date Sōdō'', which broke out among the Date family ...

See also