I heard that Cantonese was spoken all over the country during the Tang Dynasty. Is it true?/You don't say.

Only modern Cantonese (Cantonese as the standard) has preserved many language pronunciations and expressions of the Tang Dynasty in China. Indeed, when reading the poems of Li Bai, Du Fu and Bai Juyi (especially long poems, such as Shu Dao Nan and Pipa Xing). ), you will find that in some places where Mandarin is difficult to rhyme, Cantonese is easy to rhyme.