Ambleteuse is a commune in the Pas-de-Calais department in northern France.

In the course of his Gallic Wars, Julius Caesar invaded Britain twice: in 55 and 54 BC. On the first occasion, Caesar took with him only two legions, and achieved little beyond a landing on the coast of Kent. The second invasion consisted of 800 ships, five legions and 2,000 cavalry. The force was so imposing that the Celtic Britons did not contest Caesar's landing, waiting instead until he began to move inland. Caesar eventually penetrated into Middlesex and crossed the Thames, forcing the British warlord Cassivellaunus to pay tribute to Rome and setting up Mandubracius of the Trinovantes as a client king. The Romans then returned to Gaul without conquering any territory.