Although agricultural literature from the Han and Tang Dynasties offers a rich source of information on textile raw materials and processing techniques, not a single piece of Chinese textile has been found and linked to these centuries. It appears that a nationwide system of production and distribution was established under the Han Dynasty (206 BC to AD 220), but it was severely damaged during the subsequent period of intense war between the split Chinese kingdoms. Family-based textile production appears to have been the major source of state revenue throughout much of China in the years between the Han and the Tang Dynasties.