 What followed was a border war in 1277 – 78 . It was reported mainly in the Yuan dynasty chronicle and the travelogue of Marco Polo . Although the Burmese chronicles have no record of the border war , a 1278 Burmese inscription mentions the army 's defeat at Ngasaunggyan . The Mongol accounts of the border war contain certain errors of location and numbers although the overall narrative is probably accurate . 
