Longue Island was named for its long shape by Captain Nicholas Morphey in 1756. It is 800 metres long and 300 metres wide. It is situated 5.6 kilometres east of Mahe Island. Sainte-Anne Marine Park surrounds the islands near Longue including Moyenne, Cerf, Round, Cachee and St. Anne Islands.
Captain Morphey was French/Irish from Brittany. He arrived at what is today Seychelles, on the Cerf accompanied by Captain Prejean on the Saint Benoit. They celebrated the feast of Sainte Anne, who is the patron saint of Breton corsairs and other seamen, on September 9th, 1756. At that time, Morphey named Cerf Island after his ship and Sainte Anne Island in homage of his patron saint.