The Đại Việt–Lan Xang War of 1479–84, also known as the White Elephant War, was a military conflict precipitated by the invasion of the Lao kingdom of Lan Xang by the Vietnamese Đại Việt Empire. The Vietnamese invasion was a continuation of Emperor Lê Thánh Tông's expansion, by which Đại Việt had conquered the kingdom of Champa in 1471. The conflict grew into a wider conflagration involving the Ai-Lao people from Sip Song Chau Tai along with the Mekong river valley Tai peoples from the Yuan kingdom of Lan Na, Lü kingdom Sip Song Pan Na (Sipsong Panna), to Muang along the upper Irawaddy river. The conflict ultimately lasted approximately five years growing to threatened the southern border of Yunnan and raising the concerns of Ming China. Early gunpowder weapons played a major role in the c