For most of time since the establishment of the Ming Dynasty in the second half of the 14th century till the early 1980s, trading with the rest of the world was banned or restricted in China. By contrast, right before Ming’s closed door policy, China had already been involved in an enormous maritime trade for hundreds of years. And before it explored trade on the sea, its trade with Europe via West Asia and the Arabian Peninsula on the Silk Road had been going on for hundreds of years.   The Southern Song was a smaller, weaker dynasty than the Tang or Northern Song, but it was the richest dynasty in China’s history. It ruled the Yangtze River and Pearl River areas, the most prosperous regions in China. Maritime trade reached its peak in this period, contributing a lot to the prosperity of the dynasty.