In 1520, Photisarath came to the throne and moved the capital from Luang Prabang to Vientiane to avoid a Burmese invasion. Setthathirath became king in 1548, after his father was killed, and ordered the construction of what became the symbol of Laos, That Luang. Settathirath disappeared in the mountains on his way back from a military expedition into Cambodia, and Lan Xang fell into more than seventy years of instability, involving both Burmese invasion and civil war.