in the northern and southern dynasties when the state of chen (a.d. 557-589) was facing its demise（死亡，终止） , xu deyan, husband of the princess, broke a bronze mirror into halves. each of them kept a half as tokens（代币，符号） in case they were separated. soon afterwards, they did lose touch with each other, but the two halves of the mirror enabled them to be reunited.
this idiom is used to refer to the reunion of a couple after they lose touch or break up.
破镜重圆的故事

　　"镜子"是中国传统文学中是一个广泛使用的文学意象。文学家把满月比作镜子，也用镜子来形容一个人的品德无暇疵，还有的时候说某某人的心里明镜似的，形容他对事情的明晰洞察。成语"破镜重圆"是借镜子比喻离散夫妻重新团聚的。
故事发生在公元九世纪，当时中国北方是强盛的隋政权，南方则并存着好几个小国家，国都在建康（今南京）的陈国就是其中的一个。隋政权对南方的小国家虎视耽耽，随时准备统一整个中国。

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