Royal kin and queens · The Kamakura house and its housemen · as at first light, 1 January 1200

Senman (Sanetomo)

Senman is seven, the second son of the dead shogun and of Masako, and the Hōjō's other candidate.

He holds nothing and does nothing, but he matters because the family that raises him is Masako's. If Yoriie falls ill or is deposed, the housemen have a choice: Yoriie's son Ichiman (a Hiki grandson) or Senman (a Hōjō nephew). On the likely course the Hōjō make that choice for them in 1203. In 1200 he is a boy in the household whom the Hōjō guard.

Who he is

Name
Senman (named Sanetomo by the court in 1203)
Title
Younger son of Yoritomo; a child with no office; childhood name Senman
Since
not applicable
Born
1192 (Kenkyū 3/8/9, about 17 September Julian); seven by the Western count
Family
Second son of Yoritomo and Hōjō Masako; nursed by Awa no Tsubone, Masako's sister; his guardians are in effect Masako and the Hōjō. His bride, a daughter of the Kyoto courtier Bōmon Nobukiyo, comes only in 1204: not yet.
Confidence
medium

Brief; Masako's family from English Wikipedia (Hōjō Tokimasa).

Overlord

Yoriie (his brother) and Masako (his mother)

What it holds

  • Nothing in his own right; a place in Masako's household

How it was acquired

By birth.

Allies and rivals

Raised by Awa no Tsubone and the Hōjō; the rival line is Ichiman's, the Hiki.

How things stand that morning

A boy in his mother's household. Nothing is recorded of him for the winter.

Threats

  • Any plot of the Hiki, if the sources of 1203 are right

What the year holds

What happened next, if nothing in play changes it. Each event carries what it depends on and what would stop it.

  1. Kennin 3/7 to 9 (about August to October 1203)Yoriie divides the realm between Ichiman and him; after the Hiki fall he is named successor and the court gives him the name Sanetomo; he is shogun at eleven.Depends on: The Hiki-Hōjō quarrel Stopped by: Yoriie's recovery
  2. 1204He marries the daughter of Bōmon Nobukiyo.Depends on: The conditions of 1 January 1200 continuing: no player action in the east that changes them is assumed. Stopped by: The bridegroom's death, a change of Hōjō policy, or the court's choice of another bride.

Where the sources disagree

Evidence: Birth and parentage are certain; nothing else is known for 1200.

On the map: Not drawn.

Primary sources for Kamakura regime

Chronicles, registers, sagas and inscriptions written in or near 1200 that cover this entry. Each has its own page with editions, translations and where to read it.

  • Hundred Times Refined Extracts: court annals (late thirteenth century, from court diaries). Short dated annals of the imperial court excerpted from courtiers' diaries, among them the Gyokuyo and the Meigetsuki. Read online
  • Mirror of the East, Anonymous; compiled by officials of the Kamakura shogunate (compiled about 1300 from the shogunate's records, diaries and family documents). The Kamakura house's own chronicle, in daily entries. Read online
  • Jottings of a Fool: an interpretative history of Japan, Jien (慈円) (about 1219 to 1220, revised to about 1223). A history by Kujo Kanezane's brother, head of the Tendai school and the leading churchman of the court, written to explain the fall of the Kujo and the rise of the warriors as the working of principle (dori). Read online
  • Diary of the Inokuma Regent: the diary of Konoe Iezane, Konoe Iezane (近衛家実) (1197 to 1218, as a daily diary). The diary of the regent's heir, aged twenty-one in 1200 and already a senior courtier under his father Konoe Motomichi, who was regent (sessho) for the child emperor Tsuchimikado. Read online
  • Leaves of Jade: the diary of Kujo Kanezane, Kujo (Fujiwara) Kanezane (九條兼實) (1164 to 1200, as a daily diary). The diary of the former regent, Yoritomo's ally at court, who had been driven from power in the Kenkyu purge of 1196 and lived in retirement in 1200. Read online
  • Record of the Bright Moon: the diary of Fujiwara no Teika, Fujiwara no Teika (藤原定家) (1180 to 1235, as a daily diary, with gaps). The diary of the poet and courtier, then thirty-eight and a middle-ranking official of the Kujo house. Read online
  • Surviving Documents of the Kamakura Period, Various; collected by Takeuchi Rizo (竹内理三) (documents of 1185 to 1333, collected and printed 1971 to 1997). The collected charters, deeds, court orders, shogunal directives, temple records and land registers of the Kamakura age, printed in date order. Read online
  • The Tale of the Heike, Anonymous; traditionally attributed to Shinano no Zenji Yukinaga, performed and reshaped by blind reciters (early thirteenth century in its first form; the standard Kakuichi text was fixed in 1371). The epic of the Genpei war, in the form the reciters gave it over the century after 1200. Read online

Sources and studies

  1. KJA_BRIEF.md and the OMNIA board for sheet kja (the lead's notes: [own] computation, [not yet checked against the source] recollection, [en] English Wikipedia)
  2. Azuma Kagami (the Kamakura chronicle), Kenkyu 10 to Shoji 2 entries, recalled and through the brief; ja.wikipedia and ja.wikisource were refused in this session, so no entry was re-read
  3. Jeffrey P. Mass, Warrior Government in Early Medieval Japan (1974), from memory; the archive.org full text could not be opened

Last revised 4 November 2026. Published 4 November 2026. Suggest a correction on the OMNIA Discord.