 The inner line was the forerunner to the Ming Great Wall.In 1373, as Ming forces encountered setbacks, Hongwu put more emphasis on defence and adopted Hua Yunlong's (華雲龍) suggestion to establish garrisons at 130 passes and other strategic points in the Beijing area.More positions were set up in the years up to Hongwu's death in 1398, and watchtowers were manned from the Bohai Sea to Beijing and further onto the Mongolian steppes.