[11][a] Because of the irregularity of Chinese supply and the frequency of Korean famines, Mao also established farming colonies on the nearby mainland at Cholsan ("Tieshan"), Changsong ("Changcheng"), and Uiju ("Yizhou").

[13] He attempted to negotiate an official free trade policy between China and Korea, ending their remaining sea bans and restrictions on exportation of goods considered strategically important, but also aimed to restrict Korea's direct tributary trade with China, instead driving its goods to his markets.

[13] He charged visiting merchants high taxes but protected all comers,[13] including raiders[14] and smugglers,[13] and so drew in much of the Yellow Sea trade between Manchuria, China, and Korea.

[13][8] Scholars estimate he was able to collect tens of thousands of silver tael a year;[13] he also sought supplies of Korean copper and iron to mint his own currency.

[14] As preparation for the Manchu's second invasion of Korea, Hong Taiji traveled to Zhenjiang and sent Abatai, Jirgalang, and Ajige to secure its western coast in the 12th lunar month of 1636.

In the end, Ming and Korean defectors including Kong Youde landed 70 boats on the eastern side of the island and drew out his garrison in that direction.