《史记·三十世家·郑世家》
昭公忽听说祭仲因宋国的要挟拥立自己的弟弟突为国君，九月丁亥日，忽逃到了卫国。
昭公忽闻祭仲以宋要立其弟突，九月丁亥，忽出奔卫。
Duke Zhao Hu heard that Ji Zhong had established his younger brother Tu as the king due to the threat of Song, and on the day of Dinghai in September, Hu fled to the state of Wei.
<s>[INST] Identify the key themes in this Classical Chinese text and explain them in English: 昭公忽闻祭仲以宋要立其弟突，九月丁亥，忽出奔卫。 [/INST] Duke Zhao Hu heard that Ji Zhong had established his younger brother Tu as the king due to the threat of Song, and on the day of Dinghai in September, Hu fled to the state of Wei.</s>
Identify the key themes in this Classical Chinese text and explain them in English: 昭公忽闻祭仲以宋要立其弟突，九月丁亥，忽出奔卫。
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Duke Zhao Hu heard that Ji Zhong had established his younger brother Tu as the king due to the threat of Song, and on the day of Dinghai in September, Hu fled to the state of Wei.
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