The Spring and Autumn Period and the Warring States Period belonged to the Zhou Dynasty, which was merged into the Eastern Zhou Dynasty (770 BC-256 BC), a dynasty in the history of China. After the demise of the Western Zhou Dynasty, the princes established the formerly abandoned Prince Yijiu as king, known as Zhou Pingwang in history and Luoyi in history (now Luoyang, Henan). The first half of the Eastern Zhou Dynasty was called the Spring and Autumn Period. In 453 BC, after the Han, Zhao and Wei clans joined hands to destroy the branch, the three clans were divided into Jin and the princes conquered each other, which was called the Warring States. ?

After Zhou Pingwang moved eastward, its jurisdiction was greatly reduced and it became a small country. Coupled with the alleged killing of his father, his prestige among the princes is not as good as before. According to Zuo Zhuan, there were 140 vassal states in the Spring and Autumn Period. In the face of the attack and merger between princes and the invasion of foreigners on the border, the son of heaven could not bear the responsibility of the Lord and often turned to some powerful princes for help. In this case, the powerful vassal will pretend to be the overlord, and the vassal of the Central Plains will "respect the king and reject the foreign countries" and unite for self-defense.

Extended data:

Lu historians recorded the major events reported by various countries at that time by year, season, month and day, and recorded them in spring, summer, autumn and winter in a year. In a word, they named this chronicle Spring and Autumn Annals. Confucius compiled and revised the Spring and Autumn Annals compiled by Lu historians and became one of the Confucian classics.

"Spring and Autumn Annals" recorded the events of 242 years from the year of Lu Yin (722 BC) to the fourteenth year of Lu Aigong (48 BC1year). Because the starting and ending years of the historical facts recorded in it are roughly equivalent to an objective historical development period, historians of all dynasties have used the title of Spring and Autumn Annals as the name of this historical period. For the convenience of narration, the Spring and Autumn Period began in 770 BC (the first year of Zhou Pingwang) when Zhou Pingwang moved eastward to the Eastern Zhou Dynasty, and ended in 476 BC (the forty-fourth year of Zhou Dynasty) on the eve of the Warring States Period, with a total of 295 years.

References:

Baidu Encyclopedia-Eastern Zhou Dynasty?