Louis Aleno de St Aloüarn

Louis Francois Marie Aleno de Saint Aloüarn (; 25 July 173827 October 1772) was a French Navy officer and explorer who claimed French Western Australia.

St Aloüarn made the first formal European claim of sovereignty — on behalf of France — over the west coast of Australia, which was known at the time as "New Holland". Much of this west coast had already been charted by other mariners from the Netherlands, following a landing by Dirk Hartog in 1616, who left a commemorative plaque recording his visit. James Cook, in 1770, had charted and claimed the east coast for Britain. When St Aloüarn visited New Holland in 1772, neither British nor Dutch officials had issued a formal claim over this western part of New Holland. However, the French claim over Western Australia was never secured by a permanent settlement.

Early life and military career St Aloüarn's parents were François Marie Guénolé Pantaléon d’Aleno and Marie Josèphe Pélagie de Quillien, both members of the aristocracy. He was born at Saint-Aloüarn, near Guengat, Brittany.

The family, including St Aloüarn's father, had a history of service in the French Navy, and St Aloüarn joined the Gardes de la Marine in 1754. As a naval cadet, he joined his uncle, René de Rosmadec St Aloüarn, on the 74-gun warship Espérance. During 1759–62, St Aloüarn served in France on smaller vessels and on shore. He was a Freemason, member of the Loge Parfaite Union of Quimper.

Career as an explorer In 1771, shortly after the death of his wife, St Aloüarn was approached by a colleague, Yves de Kerguelen, who asked him join an expedition to New Holland. This reflected a broader French drive to annex territories adjoining the Indian and Pacific Oceans. Kerguelen and St Aloüarn first travelled to Port Louis, Isle de France (now Mauritius). On 17 March he arrived off a bay (later Flinders Bay), near the cape. With no sign of Kerguelen, St Aloüarn followed the coast northward.

At Baie de Prise de Possession ("Bay of Taking Possession"; later Turtle Bay), Dirk Hartog Island on 30 March 1772, officer Jean Mengaud de la Hage claimed French Western Australia, the first formal European claim in Western Australia, on behalf of King Louis XV while St Aloüarn remained aboard the ship. This occurred in sight of Cape Inscription, where in 1696 the Dutch mariner Willem de Vlamingh had also left a commemorative plate recording his visit and that of Dirk Hartog in 1616.

Aftermath By the time of the annexation, many of the crew of Gros Ventre were exhausted and suffering from scurvy. A British Army force, under Major Edmund Lockyer, was despatched from Sydney, establishing a permanent British settlement at King George Sound, named Frederick Town (or Frederickstown), later known as Albany.

Searches for the annexation site During the late 20th century, historian Leslie Marchant, one of whose specialities was the French exploration of Australia, and others, led expeditions that attempted to find the site of St Aloüarn's proclamation. However, the site was not located until January 1998, when an expedition, led by amateur archaeologists Philippe Godard and Max Cramer, visited Dirk Hartog Island and located an écu coin in a lead capsule, at Turtle Bay.

Searches continued for a bottle reportedly buried by St Aloüarn's crew, containing a document proclaiming France's annexation of Western Australia. In April 1998, a WA Maritime Museum expedition, including archaeologists and remote sensing specialists, located a bottle, capped with a lead seal surrounding another écu; however, the bottle contained only sand.

The proclamation site was later protected by law and a commemorative plaque was placed at the spot.