Varieties of Chinese
Evidence for dialectal variation is found in texts from the Spring and Autumn period (722–479 BC).  At that time, the Zhou still defined a standard speech.  The Fangyan (1st century CE) studies the differences in vocabulary between regions. Texts from the Eastern Han period also discuss local differences in pronunciation. The Qieyun rhyme book (601) noted wide variation in pronunciation between regions. It wanted to define a standard pronunciation for reading the classics. This standard is called Middle Chinese.