Before the development of paper, silk and bamboo slips were mainly used to record words, at this time classical Chinese was still the written and spoken language of the ancestors, but in the continuous migration, classical Chinese became the patent of readers, and the spoken language continued to integrate foreign civilizations when migrating, so different regions produced different spoken languages, that is, dialects. 
Dialects in thousands of years of evolution, phonetics, vocabulary, grammar are changing, thousands of years of development, dialects have long become living fossils, domestic experts also believe that dialects and dialects are independent languages, although there are many sub-dialects, but linguists only divide seven dialects. Northern dialects (official dialects listed as;Poverty, poverty, rubbing, etc.), Wu dialect, Hunan dialect, Hakka dialect, Min dialect, Cantonese dialect, Jiangxi dialect. 
The northern dialect is based on the Beijing dialect, and there is also a Chinese official dialect, and the people who use the northern dialect are also the most, and the region is wider, and the northern dialect is subordinate to the Beijing official dialect, the Central Plains official dialect, and the Northeast official dialect, although the northern dialect is spoken by nearly 73% of the Han people, but it is not the oldest. The oldest is the Hakka dialect, the Hakka language is the mother tongue of the Hakka people, the Hakka people have become the oldest living fossils in the history of more than 2,000 years, the Hakka people originated from the Qin State to conquer Baiyue and was born of a group, after the Wei, Jin, Southern and Northern Dynasties, Tang, Song, Yuan, Ming and Qing dynasties, has formed the most special ancient civilization. 
The Hakka people not only retain the oldest language, but also maintain the Han Dynasty Dock Fort in terms of architectural style and form, the most distinctive of which is the Wailong House, the earthen house, the Hakka Wai Long House was built in the Tang Dynasty, the Ming Dynasty was the most prosperous, the Wailong House is also known as the "Oriental Ancient Roman Castle" The dock fort of the Han and Jin Dynasties is known as one of the five major characteristics of China in the history of architecture, and today's Hakka people are also the most widely distributed ethnic groups in China, as the saying goes: "Where there is seawater, there are Chinese, and where there are Chinese, there are Hakka." 
The Hakka migration history can be said to be half of the Chinese historical dictionary, the Hakka people have a total of five large migrations, the first Western Jin Dynasty Yongkang first year (AD 300) in the Western Jin Dynasty occurred in the Western Jin Dynasty "Eight Kings Rebellion" royal nobles have seized power, the northern Xiongnu, Xianbei, Qiang, Di, and Qiang took advantage of the void to enter, known as the Wuhu Rebellion. The second time was the Anshi Rebellion in the Tang Dynasty, the third time was the difficulty of Jingkang, the fourth time was the entry of Qing soldiers, and the fifth time was the Taiping Heavenly Kingdom Movement. 
Hakka language has been initially formed in the Southern Song Dynasty, its language is inherited from the ancient language, ancient Chinese is the ancient language of Yin Shang, ancient is the language style formed in the Western Zhou Dynasty, the official language was gradually formed at this time, Cao Wei to the Southern Song Dynasty formed the Middle Chinese, Hakka language is inherited from the Middle Chinese. 
The rest of the dialects were developed from the modern ancient language, but the Hakka language still retains the characteristics of the Middle Ages in the course of change.