1 Cash - Nguyên Phong Thông Bảo; Running script

Nguyên Phong was the reign title of Trần Thái Tông, the first emperor of the Trần dynasty, who held the throne while Vietnam was under existential pressure from the Mongol Empire. The first Mongol invasion came in 1258, the final year of this reign period, when Kublai Khan's forces briefly occupied Thăng Long before being repelled — one of the earliest successful resistances to Mongol expansion in Southeast Asia. Coins bearing this era name were therefore circulating at precisely the moment the dynasty faced its first military catastrophe.

The running script designation distinguishes this type from the more common standard-script Nguyên Phong issues catalogued by Toda.