From 1823 to 1847, Vietnamese court vessels loaded with Vietnamese products sailed to the colonized cities of island Southeast Asia almost every year.
Careful reading of the essential court document, Dai Nam Thuc Luc (Primary collection of the veritable records of Dai Nam), makes you form the concrete outline of the court vessel trade. Newly found evidence from the volumes of Chau Ban (Vermilion records of Nguyen dynasty) will show you the detail list of goods that were sold and purchased in the island Southeast Asia cities. The diaries of civil officials are also important because we would be able to know how they traveled and what they were interested in. Phan Huy Chu, for example, left substantial descriptions on American steamships, Chinese settlers in Batavia, Western custom, and the history of colonization of the region.
Until now, the voyage has been understood as the court monopoly of overseas trade and the work of purchasing luxurious commodities for royal use.
This paper, however, considers different aspects. It emphasizes two main purposes of the court vessel trade in island Southeast Asia: one was to purchase military equipments, the other was to collect information in the colonized regions. Together with artisans, medical doctors, and students who were supposed to learn new mechanical skills and foreign languages, high-ranking mandarins were sent to the regions. The mission of the mandarins was to observe the colonized regions and to report the situation to Vietnamese court.
In addition, I tentatively raise the question of Western impact on the young high-ranking mandarins who experienced colonized regions and on the intellectual world of Vietnam as a consequence. Cao Ba Quat, was a civil official who had visited Batavia on the court vessel. Afterwards, he took part in a famous anti-government revolt that broke out in 1854. Vietnamese intellectuals were seeking change before French invasion in 1858, and the court vessel trade was, I think, one of the most important vehicles that brought motivation for the change.