Career
Tromelin joined the navy in 1800, and served on various ships during the Napoleonic wars, before gaining command of the corvette Bayonnaise in 1826 and on 21 December sailed from Toulon for South America, via the Hawaiian Islands, where he was to report on the political situation and ease the plight of French missionaries. He visited various islands of the Pacific en route, and returned to Toulon 19 March 1829. In August 1849, he occupied the fort of Honolulu.
Phoenix Island
While aboard the corvette Bayonnaise, Tromelin came across Sydney Island and Phoenix Island, probably in 1828, although some sources state 1823 and 1826.
Placing the island at 3°42"South, 189°17"East, Tromelin claimed it was already reported on Norie"s map. A "Phenix", plus unnamed islands at similar coordinates feature in Jeremiah North. Reynolds"s 1828 report to the American Navy, but the source of the name (and discoverer) remains contentious.
Fais Island
Tromelin is sometimes credited for the discovery of Fais Island, although that honour might also belong to Francisco de Castro, whose sixteenth century journey to the Philippines took him through the Caroline Islands.