Book of the Later Han - Chinese Historical Work
The History of the Later Han (后汉书) is one of the official Chinese historical works which was compiled by Fan Ye in the 5th century, using a number of earlier histories and documents as sources. It covers the history of Eastern Han from 25 to 220 CE.
The book is part of early four historiographies of the Twenty-Four Histories canon, together with the Records of the Grand Historian, Book of Han and Records of Three Kingdoms. Fan Ye used a number of earlier histories, including those accounts by Sima Qian and Ban Gu, plus many others (some that were also entitled name resemble to the work, such as the Han Records of the Eastern Lodge by various contemporaries throughout the 2nd century or the Records of Later Han by Yuan Hong from the 4th century) most of which have not survived intact. The final 30 volumes of the book or the 8 treatises on law, rituals, sacrifices, astronomy, five elements, geography, officials, chariots and garments taken from the Sequel of the Book of Han, a work composed by Sima Biao in the 3rd century were added in the 6th century by Liu Zhao during his annotation.
The Records of the Western Regions are based on a report composed by General Ban Yong and presented to the Emperor about 125, probably included notes by his famous father, General Ban Chao. It forms the 88th volume of the Hou Hanshu and is a key source for the cultural and socio-economic data on the Western Regions, including the earliest accounts of Da Qin (the Roman Empire).
Fan Ye, himself, clearly says that the new information contained in this section on the Western Regions, is largely based on information from the report of General Ban Yong to the Emperor c. 125 CE.
"Ban Gu has recorded in detail the local conditions and customs of each kingdom in the former book [Hanshu or 'History of the Former Han Dynasty']. Now, the reports of the Jianwu period [25-56 CE] onwards recorded in this 'Chapter on the Western Regions' differ from the earlier [ones by Ban Gu]; they are from Ban Yong’s report [presented] at the end of [the reign of] Emperor An [107-125 CE], and so on."