In 1533 he moved his court to Vientiane, the commercial capital of Lan Xang which was located on the floodplains of the Mekong below the capital at Luang Prabang. Vientiane was the principal city of Lan Xang, and lay at the confluence of trade routes, but that access also made it the focal point for invasion from which it was difficult to defend. The move allowed Photisarath to better administer the kingdom and to respond to the outlying provinces which bordered the Đại Việt, Ayutthaya and the growing power of Burma.