The kingdom went into decline in the mid-13th century as the continuous growth of tax-free religious wealth by the 1280s had severely affected the crown's ability to retain the loyalty of courtiers and military servicemen. This ushered in a vicious circle of internal disorders and external challenges by the Arakanese, Mons, Mongols and Shans. Repeated Mongol invasions (1277–1301) toppled the four-century-old kingdom in 1287. The collapse was followed by 250 years of political fragmentation that lasted well into the 16th century.