There are few records on the early history of the Qoco Uighur Kingdom in traditional Chinese historical sources. This paper attempts to study the newly published Chinese document BD11287, which reveals that the Qoco Uighur Kingdom underwent its toughest time and was confined to the city of Qoco during the period 866-876(presumably 866-869). The paper thereby attempts to outline the development of the Qoco Uighur kingdom between the seventh year of the Xiantong era and the Qianfu era.
