Ambleteuse, a small decayed seaport of France, on the English channel, in the department of Pas-de-Calais, 5 m. N. of Boulogne. Here James II. landed on his flight from England in 1689. Napoleon, while meditating an invasion of England in 1804, attempted unsuccessfully to improve the harbor of Ambleteuse for his flat-bottomed boats. In the vicinity is the famous granite column erected by Napoleon to the grand army in 1805.