The Chinese province of Yunnan -- where the Mekong River , previously used for illegal migration , flows - is China 's main avenue for trade with the Nanyang .
Chinese merchants were constantly pushing south as trade with Burma thrived .
The Chinese province of Yunnan -- where the Mekong River , previously used for illegal migration , flows - is Chinese 's main avenue for trade with the Nanyang .
Chinese merchants were constantly pushing south as trade with Burma thrived .