Twice in history, Burmese capitals fell to Tai powers from the north. In the first case, the twin capitals of Pinya and Sagaing were devastated in the early 1360s by the forces of Mäng Mao, a domain located in the modern Yunnan-Burma borderlands. The emergence of Mäng Mao as a major military power and its subsequent rise to trans-regional paramountcy were closely associated with and paralleled by the “Mongol Century” in China. Besides the advanced military technology of the Mongols, Mäng Mao also derived great benefit from the economic boom on a pan-Eurasian scale under the Pax Mongolica, as exotic commodities of the subtropics and precious metals as well as gems were readily available in the domain, through which the Southwest Silk Road, the principal trade artery connecting China to India, traversed.
The second capital to fall to a Tai power was Ava in 1527, right in the middle of the “Age of Commerce.” Though habitually and primarily regarded as a maritime phenomenon, the Age of Commerce also affected the deep interior of western mainland Southeast Asia, including the highland Tai world, a rich source of valuable commodities such as musk, jade, amber, and rubies, which were destined to be exported from the seaports of Lower Burma southward to Melaka and westward to India and beyond. The economic boom further activated the southward downhill movement of the Tai into the Irrawaddy Basin, ultimately leading in to the fall of the Upper Burma capital, Ava, a thriving riverine emporium.