道德經 or Dao De Jing is the foundational text of Daoism. Its 81 verses were probably recorded from the 6th century BC onwards. By the 3rd century BC, the Dao De Jing was largely established in its current form. Authorship is traditionally attributed to Lao Tzu, meaning “Old Master.” Very little is known about him though, and there may have been multiple authors.

後漢書 or Hou Hanshu, the “Book of the Later Han”, covers the history of Han China from 6 to 189 AD. This period is known as the Eastern Han dynasty because its new capital, Luoyang, was located further east than the former capital, Chang’an. The chronicle was compiled in the 5th century by Fan Ye and others, using a number of earlier histories and documents as sources.