The Lam Sơn ("blue mountain") campaign began on the day after Tết (Lunar New Year) in February 1418.Le Loi. The Encycloaedia Britannica. Micropedia, Volume VI, 15th Edition. In November 1424, the Lam Sơn captured the Nghệ An citadel in a surprise attack from their base in Laos, leading to the retreat of the ethnic-Vietnamese Ming commander Lương Nhữ Hốt (Liang Juihu) to the north. From their new base in high-density population Nghệ An, Lê Lợi's rebel forces captured the territory in modern-day central Vietnam, from Thanh Hoá to Đà Nẵng.Trần Trọng Kim, Việt Nam sử lược, vol. I, part. III, sec. XIV(1418–1427) By August 1426, the Lam Sơn rebellion launched an offensive to the north with new forces against a fresh Ming army commanded by Wang Tong in charge of defending northern Vietnam.History of Ming, 王通传 The new Ming ruler, the Xuande Emperor, wished to end the war with Vietnam, but his advisors urged one more effort to subdue the rebellious province. Consequently, the Ming sent a large army of approximately 100,000 men to Vietnam. After the pivotal Battle of Tốt Động – Chúc Động in October 1426, the Ming dynasty withdrew by 1428. By early 1427, Lê Lợi's forces had controlled most of northern Vietnam, advancing as far as the southern tip of modern-day Guangxi. Following negotiations with the Ming, Lê Lợi selected Trần Cảo as a puppet king of Annam who nominally ruled from 1426 to 1428.Ngô Sĩ Liên 1993, University of Tokyo's Toyo Cultural Research Institute, p，546－548
