The Mongols protested the move and immediately launched a second attack. The Mongol army was led by a traitor from Pyongyang called Hong Bok-won and the Mongols occupied much of northern Korea. Although they reached parts of the southern peninsula as well, the Mongols failed to capture Ganghwa Island, which was only a few miles from shore, and were repelled in Gwangju. The Mongol general there, Saritai (撒禮塔), was killed by the monk Kim Yun-hu (김윤후) amidst strong civilian resistance at the Battle of Cheoin near Yongin, forcing the Mongols to withdraw again.