The Nguyen Cochinchina was a maritime power. Its Archipelago-like landscape facing the South China Sea gave it a special character and made it stand out from all the Vietnamese dynasties. The synergy of its economy and the hybridity of its population and culture should all be seen against this background. Overseas trade defined seventeenth-century Cochinchina and regulated its labour and cash crop production on the coast and penetrated all sectors of local production and consumptions and accelerated its interactions with the uplanders. The Nguyen Cochinchina’s history challenges the conventional version of a single Vietnamese past, and the narrow strip of land between the mountains and the sea encouraged people to seek a much freer way of being Vietnamese. In such a way, it was little surprise that Cochinchina became the historical engine of change and pulled the national Vietnamese centre of gravity – whether seen in political, economic, or even cultural terms – southwards from the seventeenth century.