Nicholas Thomas Marion Dufresne was born at St. Malo on the 22nd of December, 1729, and had entered the naval service very young. On the 16th of October, 1746, he was made lieutenant of a frigate, and at the time of his offer was still only captain of a fire ship. Still he had served everywhere with distinction, and nowhere more successfully than in the Indian Seas.
The mission for which he offered himself was merely a pretext for a voyage of discovery in the Southern Seas.
Poivre, an intelligent governor and a friend to progress, approved of Dufresne's projects, and gave him detailed instructions for the enterprise he was about to undertake in the Southern Hemisphere. At this time Cook had not yet proved the non-existence of an Antarctic Continent.
Poivre would dearly have liked to have discovered the northern portion of the lands he imagined to lie near the French colonies, and where he hoped to meet with a more temperate climate. He calculated upon finding timber for masts, and many other necessaries there, such as provisions, which he was now obliged to obtain at heavy cost from the metropolis. Moreover, there might be a safe port, where vessels could find shelter from the storms which almost periodically ravaged the islands of Mauritius and Bourbon.
The government had just sent a ship's lieutenant, M. Kerguelen, to make discoveries in these unknown seas. Marion's expedition, which was to try a different route, could not fail to aid in the solution of the problem.
On the 18th of October, 1771, the Mascarin, commanded by Marion, and the Marquis de Castries, under the Chevalier Du Clesmeur, midshipman, set sail. They put in first at Bourbon Island. There they took Aoutourou on board. He was unfortunately infected with small-pox, which he had caught in the Mauritius; and the illness soon declared itself, so that it was necessary to leave Bourbon lest he should communicate it to the inhabitants. The two vessels then made for Port Dauphin, on the coast of Madagascar, in order to allow the malady to run its course, before proceeding to the Cape, where they were to complete provisioning. Young Aoutourou soon died of the disease.
Under these circumstances, was it necessary to return to Mauritius, disarm the ships, and give up the expedition? Marion thought not. With greater freedom of action, he determined to make himself famous by a new voyage, and he inspired his companions with enthusiasm like his own.
He soon reached the Cape of Good Hope, where he completed in a few days the provisioning necessary for an eighteen months' voyage.
A southerly route was chosen towards the land discovered in 1739 by Bouvet de Lozier, and which was to be looked for east of the meridian of Madagascar.
Nothing remarkable occurred from the 28th of December, 1771, the day upon which the vessels had left the Cape, until the 11th of January. It was then discovered, by taking the longitude 20° 43' east of the Paris meridian, that they were in the parallel (40° to 41° south) of the islands named in Van Keulen's chart as Dina and Marvezen, and not marked at all upon French maps.