One candidate is the Heilongjiang hand cannon, discovered in 1970, and named after the province of its discovery, Heilongjiang, in northeastern China. It is small and light like the Xanadu gun, weighing only 3.5 kilograms, 34 cm (Needham says 35 cm), and a bore of approximately 2.5 cm. Based on contextual evidence, historians believe it was used by Yuan forces against a rebellion by Mongol prince Nayan in 1287. The History of Yuan states that a Jurchen commander known as Li Ting led troops armed with hand cannons into battle against Nayan.