Although the Chinese annexation of Vietnam may have provided the technology for blue-and-white wares, economic competition was an important stimulus in their development. By the 15th century, blue-and-white wares were the most popular ceramics in the world. Active markets for them existed in East Asia, throughout Southeast Asia, and in the Middle East. The Chinese prohibition of exporting ceramics for almost thirty years during this time of high demand provided an ideal opportunity for the Vietnamese ceramic industry to expand, and the Vietnamese reliance on Chinese prototypes was most likely a deliberate attempt to capitalize on the contemporary desire for Chinese-style wares.