At the beginning of the Zhenguan Era, Emperor Taizong (599-649) of the Tang dynasty decreed that Qunshu Zhiyao (The Compilation of Books and Writings on the Important Governing Principles) be compiled. At the tender age of sixteen, Taizong enlisted himself in the army, and joined his father’s forces to try to stop the turmoil that was going on in the society. For more than ten years, he dwelt himself in military matters. After he ascended to the throne at the age of twenty-seven, he laid down his armor and began to promote culture and education, paying particular attention to the principles of governing, and bringing peace to the country. He sought to rejuvenate the nation from the aftermath of civil strife by restoring order to life, lessening the burdens of ordinary people, and increasing prosperity.