唐太宗

Li Shimin seized the throne in 626 by killing his brothers at the 玄武门之变 (Xuanwu Gate Incident) and forcing his father to abdicate. His subsequent 23-year rule - accepting blunt criticism from 魏征, expanding into Central Asia, codifying Tang law - became the benchmark 'good emperor' model for all later Chinese rulers.

Sayings from his court are everywhere in Chinese: 以铜为鉴，可以正衣冠；以史为鉴，可以知兴替 ('Use bronze as a mirror to straighten your robes; use history as a mirror to know the rise and fall of states') is his attributed eulogy for Wei Zheng and still shows up in modern political speeches.