This study is on K'ou Chun, the early Northern Sung statesman who made his name in Chinese history by the conclusion of the Treaty of Shan-yuan in 1005 with the Northern Empire of the Liao, which brought about the peace between the two countries for more than a century. Apart from discussing K'ou Chun's role in the 1004 crisis, this study attempts to view Sung bureaucratic factionalism from a new perspective through examining the activities of K'ou Chun and his t'ung-nien, candidates who obtained their chin-shih degrees in the same year. It is found that the chin-shih of the 980 examination including K'ou Chun and Wang Tan (957-1017) gradually built up a powerful faction through their t'ung-nien relationship. This faction dominated the Sung court for more than thirty years since the middle of Emperor T'ai-tsung's reign (r. 976-997). Their chief rival factions, interestingly, also came from two other t'ung-nien groups headed by Chang Ch'i-hsien (943-1014) and Wang Chin-jo (962-1025), respectively. Historically, bureaucratic factionalism always intertwined with court politics. It was no exception for early Northern Sung. Since K'ou Chun and his faction were deeply involved in the succession questions of Emperor T'ai-tsung and Chen-tsung (r. 997-1022), this study also focuses on the power struggle that took place in the inner court. K'ou Chun ultimately lost in the power struggle and died in banishment. However, his faction still managed to keep its influence during Empress Dowager Liu's (r. 1023-1033) regency when its junior members, headed by Wang Tseng (978-1038) and Lu I-chien (978-1043) gradually came to power. K'ou Chun and his faction were traditionally praised as "gentlemen", while their rivals were mostly condemned as "petty men". Such a view will be examined through the study of their behaviors. And K'ou's historical image will be explored through different perspectives as well.