The military governor and general Gao Pian 高駢 (821–887) carried out large-scale defensive works in the territories under his administration, including the fortifications of Tang Hanoi, Chengdu, and Yangzhou. This talk will focus on his outer ramparts of Chengdu, the first example of a tamped-earth construction reinforced with masonry. In addition, Gao oversaw the construction of the Channel of Heavenly Might, a hydraulic engineering feat connecting two legs of the treacherous coastal shipping lane across the Gulf of Tonkin. An inscription by the Daoist author Pei Xing裴鉶 (ca. 825–ca. 880) provides new evidence supporting Joseph Needham’s hypothesis that, with the help of alchemists, Gao Pian pioneered the use of gunpowder for rock-blasting. From a military perspective, this was significantly done in a region where ethnic minorities revered the gods of thunder and lightning.