漢代以後的政府深受儒家政治理論的影響，堯舜和三代是儒者最常提及的治國典範。唐太宗的文治武功，深為後代統治者所欣羨，而其事蹟記載詳盡，易於仿效，在中唐以後有另成典範之勢。進入五代十國時期，期待唐太宗復現的意見仍然常見，至北宋建立後，循貞觀之政以復三代之治仍是常見的政治主張。但是，從仁宗朝開始，隨著儒學的開展，部分文士開始批判唐太宗，提倡恢復堯舜三代之制以超越漢、唐。他們希望藉著政治的改革以達到重建禮樂與移風易俗的目的。 但是，當王安石、蔡京高舉「三代之法」以合理化自己的施政，反對者一方面質疑他們的具體作為不符三代的理想，一方面援引貞觀之政為典範加以對抗。堯舜三代與貞觀故事遂在部分政治論述中被描述成不同的典範。宋室南渡後，唐太宗的典範因與恢復中原的理想相吻合，再度受到統治階層的重視，而朱熹等理學家則再度嘗試重建三代的文化秩序。朱子將貞觀君臣的作為定位為以「求利」為目的，與「堯舜三代」根本不能相合，乃引發了陳亮的批判，形成了二人間的王、霸之辯。 南宋末年，程朱之學成為學術上的「正統」，文臣論政多半提倡堯舜三代而貶抑貞觀之政，但對統治者而言，「堯舜三代」邈遠而模糊，遠不如唐太宗「一統華夷」的成就來得有吸引力。從中唐至南宋末，不論儒臣對貞觀之政的評價如何改變，多數君主們對唐太宗典範的嚮往卻始終未衰。這是在分析宋神宗與王安石，孝宗、理宗與南宋理學家於施政理念的矛盾時，可以思考的角度。

In imperial China, when the political elite referred to the paradigm of governance, they usually mentioned the legacy of the There Dynasties (sandai, 三代) and the ancient sage kings, Yao (堯) and Shun (舜). In the Tang dynasty (618-907), however, a new paradigm was gradually created in the political discourse of the ruling elite. Based on the abundant achievements of Zhenguan period (貞觀, 627-649), some Tang bureaucrats suggested their emperors to follow the substantial examples of Tang Taizong (唐太宗, 599-649) rather than the vague legacy of Yao and Shun. While the Tang authority declined after the An Lushan rebellion, Taizong became the symbol of previous golden ages. Many Tang emperors demonstrated their ambition to rebuild the glory of the Tang by imitating the actions of Taizong. From the late eighth century the tradition of Zhenguan reign formed the new paradigm for political elite, and this continued even after the end of the Tang dynasty. The development of Confucianism in the Song dynasty changed the perceptions of Zhenguan reign. From the eleventh century, Song literati tried to recover the tradition of the Three Dynasties, and criticized Tang Taizong for violating the Confucian principles. From the perspectives of the emperors, however, Taizong's conquest over nomadic tribes was too attractive to be ignored. Concerned with the political paradigm, emperors and bureaucrats had different opinions, which deeply influenced the development of Song politics.