The earliest works of The Book of Songs were written in the Western Zhou Dynasty. It is the source of China's realistic poetry. According to the Book of History, On the Wind, On the Owl was written by Zhou Gongdan. This book mainly collects works from the early Zhou Dynasty to the mid-Spring and Autumn Period for more than 500 years. A batch of bamboo slips of Warring States in Tsinghua University in 2008 (referred to as Tsinghua bamboo slips for short) recorded that people celebrated drinking after defeating Li Guo, and the impromptu poem "Cricket" was closely related to the existing "Book of Songs tang style". The latest work was written in the middle of the Spring and Autumn Period. According to Zheng Xuan's Preface to Poetry, it is Martin Zhu Lin, which spans about 600 years.
1. Baidu Encyclopedia mentioned that the earliest works began in the Western Zhou Dynasty, except Xia and Shang Dynasties, belonging to the earliest Western Zhou Dynasty, so the reason is that the poetry records in The Book of Songs originated in the Western Zhou Dynasty with a long history, with an early origin and a span of 600 years, which has to be said to be a great work.
2. The Book of Songs is called the earliest, not only because of its early period, but also because it is the first collection of poems, not the first collection of poems. Summary: it can be used to modify the subject at the earliest, indicating the early period, and it can also be used to modify the poetry collection, indicating the first poetry collection.