This poem was written in the Three Kingdoms period at the end of the Eastern Han Dynasty, but because Serina Liu lived before Cao Pi proclaimed himself emperor (Wei Wendi), the dynasty was recorded as Wei and Jin Dynasties.
Liu Zhen (? ~ 2 17), a word merchant, was born in Ningyang, Dongping at the end of the Eastern Han Dynasty (now Gucheng Village, Sidian Town, Ningyang County), a famous writer in the Eastern Han Dynasty, born and raised, one of the seven sons of Jian 'an, and was famous for his five-character poems.
Serina Liu was later recruited as a vassal by Cao Cao.
Serina Liu, Kong Rong, Chen Lin, RoyceWong, Xu Gan, Ruan Yu, and * * * were collectively called "seven sons of Jian 'an" by later generations.
Good luck and hope to adopt it.