Ambleteuse began as a hamlet of a few huts in the middle of thedunes, from which the derisory name of “carcahuttes" (huts made from old-boat hulls) was once given to its inhabitants by their neighbors atAudresselles. The reason for its existence relates to the temporary needs of various invaders for conquering people from either side of theEnglish Channel. Ambleteuse is one of the candidates for the harbour thatJulius Caesar used to set out from for hisinvasion of Britain in 54 BC, thoughBoulogne-sur-Mer is the more usually accepted site.
The origin of the name of Ambleteuse remains uncertain. Some scholars claim it has Celtic origins (Ambleat), but that does not exclude the etymology "Hamel Thuys", a name given by the Saxons in the 6th century, as they too used the harbour when they emigrated toGreat Britain.
Henry VIII of England had two forts built here in 1546 to maintain a show of power towards the French kings. Ambleteuse was chosen to provide an alternative harbour, and was called the 'Newhaven.' The other fort at nearbyCap Gris-Nez, was called the 'Blackness.'[4] The forces ofHenry II of France eventually conquered them in 1549. Henry, having killed all the English prisoners, then found a stock ofcoal in the fort. This was the first time that its use was noted on the continent.
At the end of the 17th century, SébastienVauban constructedFort Mahon at the mouth of the riverSlack. This is the only coastal fort from that era that has been preserved in France, thanks to restoration promoted by Dr. Méraut and the geologist Monsieur Destombe, who together created the "Association of the friends of Ambleteuse Fort" in 1960.
Napoleon modified the estuary of the Slack to create a harbour, from where he planned to invade England in (1805). The foundations of the harbour are still visible today.
At the end of the 19th century, Ambleteuse became a popular place for holidays for people fromLille andParis. The middle classes had become interested in sea-bathing and hunting, shooting and fishing. Oyster-beds were built in the bay, to complete the ambiance of bourgeois life.