From the end of the seventeenth century, Cambodia lost control of the Mekong River course as Vietnamese force ventured into the lower Mekong. Amid the Nguyen-Siamese War (1717 - 18) a Siamese armada smoldered the port of Kompong Som in 1717 yet was vanquished by the Vietnamese at Banteay Meas/Ha Tien. A Cambodian ruler of the late eighteenth century, Outey-Reachea III partnered with a Chinese privateer, Mac-Thien-Tu, who had built up a self-governing nation situated in Ha Tien and controlled the oceanic system on the eastern piece of the Gulf of Thailand. Ha Tien was situated at a point where a waterway connecting to the Bassac River streams into the Gulf of Thailand. Landlocked Cambodia attempted to keep its entrance to oceanic exchange through Ha Tien. In 1757 Ha Tien procured the ports of Kampot and Kompong Som as a prize for Mac's military backing to the King of Cambodia. Until its demolition in 1771 the port formed into an autonomous obligation free entrepot - connected with a few Chinese exchanging systems.
Alexander Hamilton, who went on the Gulf of Thailand in 1720, composed that "Kompong Som and Banteay Meas (later Ha Tien) fit in with Cambodia, as Cochin-China was partitioned from Cambodia by a waterway (Bassac stream) of three groups wide." and "Ruler Ang Duong developed a street from his capital of Udong to Kampot". Kampot remained the main universal seaport of Cambodia. "The voyaging time in the middle of Udong and Kampot was eight days by oxcart and four days by elephants." French Résident Adhemard Leclère composed: "...Until 1840s, the Vietnamese represented Kampot and Péam [Mekong Delta], yet Kompong Som fit in with Cambodia. The Vietnamese built a street from Ha Tien to Svai town - on the fringe with Kompong-Som - by means of Kampot."
The British Empire took after a particular strategy by the 1850ies, looking to unite its impact. Observer reports give uncommon bits of knowledge, as Foreign Secretary Lord Palmerston'sagent John Crawfurd reports: "Cambodia was...the Keystone of our arrangement in these nations, - the King of that antiquated Kingdom is prepared to toss himself under the security of any European nation...The Vietnamese were meddling with the exchange at Kampot, and this would be the premise of an approach..." Palmerston closed: "The exchange at Kampot - one of only a handful few remaining ports, could never be significant, in result of the principle access to the nation, the Mekong, with every one of its feeders streaming into the Sea through the domain of Cochin China The nation, as well, had been crushed by late Siam - Vietnam wars. Accordingly, without the guide of Great Britain, Kampot or some other port in Cambodia, can never turn into a business Emporium." Crawfurd later composed: "The Cambodians... looked to utilize interims of peace in the Siam -
wars to create intercourse with outside countries. The exchange at Kampot which they looked to cultivate was risked by privateers. Here is a point where the wedge may be embedded, that would open the inside of theIndo-Chinese Peninsula to British Commerce, as the immense River of the Cambodians navigates its whole length and even manages correspondence into the heart of S
