In 1900, a cave filled with tens of thousands of manuscripts was discovered near the oasis town of Dunhuang 敦煌 in northwest China. This dissertation, based on some 450 codices recovered from this cave, examines the codex culture in tenth century Dunhuang and explores the early history of the codex in the Sinophone world. Inspired by western codicology and palaeography, this dissertation pays particular attention to the materiality of manuscripts and reconstructs their production and use as well as the human activities and the specific circumstances that shaped the manuscripts. This dissertation includes a wealth of technical details about the codex production, which supplements the history of the Chinese book and benefits comparative codicological research. The dissertation also relates the materiality of manuscripts to the larger dimensions of the past and explores various research topics regarding the social and cultural history of local society, including medieval Buddhism, education and cultural exchange on the Silk Road.