Contributions

Agriculture and education

While waging military campaigns against his enemies, Cao Cao did not forget the basis of society – agriculture and education.

In 194, a locust plague caused a major famine across China. According to the Records of the Three Kingdoms, the people ate each other out of desperation. Without food, many armies were defeated even without fighting. From this experience, Cao Cao saw the importance of an ample food supply in building a strong military. He began a series of agricultural programs in cities such as Xuchang and Chenliu. Refugees were recruited and given wastelands to cultivate. Later, encampments not faced with imminent danger of war were also made to farm. This system was continued and spread to all regions under Cao Cao as his realm expanded. Although Cao Cao's primary intention was to build a powerful army, the agricultural program also improved the living standards of the people, especially war refugees.

By 203, Cao Cao had eliminated most of Yuan Shao's force. This afforded him more attention on construction within his realm. In autumn of that year, Cao Cao passed an order decreeing the promotion of education throughout the counties and cities within his jurisdiction. An official in charge of education matters was assigned to each county with at least 500 households. Youngsters with potential and talents were selected to undergo schooling. This prevented a lapse in the output of intellectuals in those warring years and, in Cao Cao's words, would benefit the people.

Poetry

Cao Cao was also an established poet. Although few of his works remain today, his verses, unpretentious yet profound, contributed to reshaping the poetry style of his time. Together with his sons Cao Pi and Cao Zhi, they are collectively known as the "Three Cao" in poetry. Along with several other poets of the time, their poems formed the backbone of what was to be known as the jian'an style (建安風骨; jian'an is the era name for the period from 196 to 220).

The civil strife towards the end of the Eastern Han Dynasty gave the jian'an poems their characteristic solemn yet heart-stirring tone, which frequently lament over the ephemerality of life. In the history of Chinese literature, the jian'an poems were a transition from the early folksongs into scholarly poetry.

One of Cao Cao's most celebrated poems, written during a campaign against the northern Wuhuan in 207, is Though the Tortoise Lives Long (龜雖壽).