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surrender of a castle; surrender of a fortress; capitulation of a stronghold
長い籠城の末に開城を決断した。
After a long siege, they decided to surrender the castle.
無血開城により多くの命が救われた。
Many lives were saved through the bloodless surrender.
開城の条件を巡る交渉が続いた。
Negotiations over the terms of surrender continued.