Treatise on Armament Technology, Volume 239

The land route passes through Eonyang A strategic town between Ulsan and Busan, which also provides access to Busan. General Ma Gui intended to focus the attack specifically on Ulsan. He divided his forces to seize and block Eonyang, thereby cutting off any reinforcements coming from Busan.

Li Rumei and his subordinates took over 440 heads and subsequently pressed the assault on the camp at Dosan The site of the Japanese "wajo" or coastal castle in Ulsan. Regional Commander Mao Guoqi captured or killed another 660 enemies. The Ming forces then tightly encircled the position on all four sides, maintaining a siege for ten days.

The Japanese ran out of food, and their water supply was severed. Conditions became so dire they resorted to chewing paper and drinking urine. What little food remained was given to the skilled artillerymen Shanpaozhe (善礮者): specialists in operating cannons and heavy firearms, while the rest were left to starve to death. The Ming used cannonballs made of scrap iron coated in gunpowder; a single shot could wound two men at once.

Despite this, Katō Kiyomasa original: "Qingzheng" (清正) held his position and refused to yield. Waiting for the Ming forces to grow weary, he feigned a request to surrender. Commissioner Yang Hao original: "Hao" (鎬) believed him and submitted a report to the throne, stating: "Kiyomasa begs to surrender, but I have not permitted it. I shall surely capture him alive to present before the Imperial Palace."

The veteran general Wu Weizhong cautioned him, saying: "When besieging a city, one must leave an opening Weicheng bique (圍城必缺): a classic military stratagem from Sun Tzu’s Art of War; by providing a perceived escape route, the besieger prevents the enemy from fighting with the desperate ferocity of cornered animals. If they flee, they can then be captured."

Yang Hao rebuked him. By the tenth day, reinforcements under Konishi Yukinaga original: "Hangzhang" (行長) arrived. However, fearing that our army would take advantage of their...