Why are Du Fu's poems called "the history of poetry" in the history of literature?

The theory of "the history of poetry" was first seen in Bai Meng's "The Art of Poetry" in the Tang Dynasty: "Du Fu (Fu) met the difficulties of Lushan Mountain, moved to Gansu, Sichuan and wrote poetry, and almost disappeared, so it was named" The History of Poetry "at that time. "Du Fu was a great realistic poet in the Tang Dynasty. He wrote his own experiences and feelings in the Anshi Rebellion with poetic pen, which comprehensively and profoundly reflected the social reality of this period and was called' the history of poetry'. For example, the famous narrative poems "Three Officials" (Xin 'an Official, Shi Haoguan Official, Tongguan Official) and "Three Farewells" (Newly Married, Farewell the Old, Don't Be Homeless) are full of deep sympathy, revealing the profound disasters brought to the people by this war and showing deep feelings of worrying about the country and the people.

Du Fu's poems are called "the history of poetry" for the following reasons:

1. The important historical events that are often mentioned are reflected in his poems. In the first year of Zhide (756), Tang Tao was defeated obliquely, and was later defeated by the Qing class. Du Fu had a sad Chen Tao and a sad Qingban. After recovering the two capitals, Du Fu wrote "Three Poems of Receiving Beijing" and "I am glad to hear that the government troops have been in the thief's territory for 20 rhymes"; Nine quarters of troops surrounded Yecheng, and it seems that victory is just around the corner. Du Fu wrote "Washing the Soldiers and Horses", in which he mentioned that the news of victory came one after another, and the Uighur army assisted in the operation, and was given preferential treatment in Chang 'an, and made meritorious deeds in counterinsurgency. "Three Officials" and "Three Farewells" were made in the ninth quarter when Yecheng was defeated and recruited troops along the way. 2. Some of Du Fu's poems can also make up for historical losses. For example, in "Three Exquisites", the history of killing Yuzhou and Kaizhou is written, but there is no historical record. From Du Fu's poems, we can see the chaos in Shu after An Shi Rebellion. Memories of Time Past describes the prosperous scene of Kaiyuan. His poems provide historical facts, which can prove history and make up for its shortcomings. 3. Du Fu's poems provide a broader, more concrete and more vivid picture of life than events. For example, "From Beijing to Fengxian, recite 500 words". Although some of his poems do not directly write about current events, they only write about his own feelings. However, because he is in a turbulent war, he is closely related to this disaster, his heart is on the right track, and his feelings are not divorced from the current situation. So from his feelings, we can feel some psychological state of society at that time. From the perspective of understanding the true face of history, this kind of poetry also has poetic historical significance.