The first contingent of naval troops to be sent to Newfoundland landed in Placentia in 1687. As in Acadia, it was a small force comprising 21 soldiers, one drummer, two corporals and a sergeant, commanded by Lieutenant Louis Pastour de Costabelle. 
In this very isolated location, the soldiers devoted most of their spare time to the construction of fortifications and to coastal fishing. However this work, though often punctuated with alerts and enemy attacks, did not suffice to keep the troops occupied, and their isolation had harmful effects. In addition, they were often poorly paid and badly nourished. As a result, there were a few attempts at desertion.
As the main base of French vessels exploiting the Newfoundland fishery, Placentia did not escape attack by the privateers and buccaneers of the era who scoured the seas and devastated the coasts. In February 1690, English pirates seized and pillaged Placentia after killing two soldiers of the garrison and wounding an officer. Reinforcements were sent out the following year, so that when two further attacks came in August and September 1691, the garrison was able to repulse them. Thanks to all the work done by the soldiers, Placentia had become quite well fortified by 1692, and all future attempts to take it would fail. For instance, 19 English ships attacked in late August 1693, only to be forced to retreat by the French cannon fire.