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imperial command (decree); decree of cloistered emperor
院宣が下され諸国の武士が召集された。
An imperial decree was issued and warriors from all provinces were summoned.
院宣の権威は当時絶大なものであった。
The authority of the imperial decree was tremendous at the time.
院宣を受けて源氏は挙兵に踏み切った。
Upon receiving the imperial decree, the Genji decided to raise an army.