Wu Jing Zong Yao (Outline Record of Military Affairs) by Zeng Gongliang (Northern Song Dynasty)

Since the Song Dynasty, the Chinese government had formed a clearer concept of coastal defense, and patrolled the South China Sea waters. In the Northern Song Dynasty (AD 960-1127), the courtier Zeng Gongliang undertook the compilation of Wu Jing Zong Yao under imperial decree. It is mentioned in the book that "Known as Baiyue in ancient times, Nanhai County of Guangzhou was inhabited by ethnic minorities. In the Han Dynasty, it was made a prefecture; in the Tang Dynasty, it was placed under the jurisdiction of Jinghai Regiment. In the present dynasty, Liu Chang rebuilt the towns and established a county seat. He was appointed controller of Military Training and Banditry Suppression for managing states beyond the seas and maritime transport benefits. The Han nationality and ethnic minorities lived together. The imperial army was stationed at passes, and barracks for naval patrol were established. Located at the eastern and western estuaries about 200 li from the Tunmen Mountain, the barrack base measured 280 zhang in width." This indicates that since the Song Dynasty, the Chinese government had established a shipping management agency and appointed a military commissioner in Guangnan Donglu, and set up naval patrol base camps in present-day Dongguan for patrolling the waters and maintaining maritime law and order.