《水经注·卷二十一》
吕后元年前，把孝惠帝后宫所生的儿子义封在这里，立为侯国，王莽改名为相成。
吕后元年，立孝惠后宫子义为侯国，王莽更名相成也。
Before the Yuannian Reign of Empress Lü, the son of Empress Dowager Empress Hui who was born in the harem was enfeoffed here, and it was established as a county. Wang Mang changed its name to Xiangcheng.
<s>[INST] Identify the key themes in this Classical Chinese text and explain them in English: 吕后元年，立孝惠后宫子义为侯国，王莽更名相成也。 [/INST] Before the Yuannian Reign of Empress Lü, the son of Empress Dowager Empress Hui who was born in the harem was enfeoffed here, and it was established as a county. Wang Mang changed its name to Xiangcheng.</s>
Identify the key themes in this Classical Chinese text and explain them in English: 吕后元年，立孝惠后宫子义为侯国，王莽更名相成也。
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Before the Yuannian Reign of Empress Lü, the son of Empress Dowager Empress Hui who was born in the harem was enfeoffed here, and it was established as a county. Wang Mang changed its name to Xiangcheng.
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