 In ancient China, the use of petroleum in warfare was the most effective during the Five Dynasties and Ten Kingdoms period and the following four major dynasties and powers from Song through to Yuan, including the Jin Dynasty and Liao Dynasty.During this time a small dynasty in Vietnam paid tribute to the Chinese emperor with petroleum.Before this time, fire attacks were limited to burning wood or animal fat; using petroleum greatly increased the potency of fire attacks, and the fact that trying to douse the burning petroleum with water will only spread the fire more rapidly made burning oil an ideal weapon for destroying cities filled with wooden structures.