In 1548, the Ming suffered a defeat at the hand of [G 01 / Altan Khan] (1507-82), the Mongol leader who had brought unity to the [G 22 / steppe] and attempted to deal peacefully with the Chinese. This was followed by another rout the following year. These raids were in response to trade restrictions imposed by the Ming. The [G 12 / Mongols] raided after each refusal to open trading - a process that continued for the next 30 years.
Mongol settlements on the border posed an additional threat to the Chinese. With continued refusals to trade, they made further threats to attack Beijing. However, when the attacks came, [L3 316 / Weng Wan Da's] defence held firm and the nomads were unsuccessful. The area northeast of Beijing was relatively unguarded though, and in 1550 the Mongols rode on Beijing from this direction.
Arguments for opening trade barriers to the Mongols continued to be presented by some within the Ming court. Among the points in favor of trade relations was the belief that a period of peace could give the Chinese time to strengthen their border defences and build fortified villages.
Prohibition of maritime trade in southeast China's coastal provinces in the mid-16th century was similar to the prohibitions used against the Mongols in the north.
