BOULOGNE-SUR-MER, town of north France, capital of an arrondissement in the department of Pas-de-Calais, on the English channel at the mouth of the river Liane, 157m. N.N.W. of Paris on the Northern railway, and 28m. by sea S.E. of Folke stone, Kent. Pop. (1931) 50,312. On the site of the Roman har bour Gessoriacum which later became Bononia, it was destroyed by the Normans in 882, but restored about 912. In Carolingian times it was head of a countship, long an object of dispute between Flanders and Ponthieu. It belonged to the houses of Ponthieu (965-1234), Brabant and Auvergne, until seized by Philip the Good, duke of Burgundy, in 1419. In 1477 Louis XI. of France reunited it to the Crown. In Henry VIII. of England took the town by siege; but it was restored to France in 155o. From 1566 to the end of the 18th century it was the seat of a bishopric. Boulogne stands upon hills skirting the right bank of the Liane with the industrial quarter, Capecure, on the left bank. The town includes Haute Ville and Basse Ville. The former, on the hill top, is a comparatively small parallelogram surrounded by 13th century ramparts with boulevards outside. Here are the law court, château and hotel-de-ville (18th century), and a belfry tower (13th and 17th centuries). At some distance north-west stands the church of Notre Dame (1827-66), a well-known place of pilgrimage, on an old site. The modern town stretches from the foot of the hill to the harbour. The public buildings include a museum of antiquities, natural history, porcelain, etc., con nected with the public library, containing 75,000 volumes and valuable manuscripts, many of them richly illuminated. The Colonne de la Grande Armee, begun in 1804 and finished under Louis Philippe, commemorates Napoleon's projected invasion of England. The harbour is formed by the mouth of the Liane. The town and port were under British administration and devoted to military uses in 1914-18, and formed the main channel for reinforcements. The equipment of the port was largely developed in 1914-18 and the Loubet basin (1925) has increased the quay length. Railway improvements (1924) enable expresses from Calais to pass through Boulogne at high speed, and a scheme to rebuild the maritime station and construct a tunnel to connect with the main line at Outreau has been approved. Har bour works (1924) are to provide accommodation for large liners which, it is hoped, will make Boulogne a port of call. The Liane estuary, behind the old harbour, is to be converted into an inner harbour and dock for the important fishing industry. Boulogne imports hams, jute, wool, woven goods of silk and wool, kaolin, coal, slates, timber, machinery, and iron and steel, and exports wine, brandy, woven goods, fruit, potatoes and other vegetables, poultry, objects of art, stone and cement. Raw Italian silk is shipped in large quantities to England. Herring and mackerel fishing are very important, much fish being sent to Paris by rail way; and boats are sent to the Newfoundland beds for cod. The fishermen live for the most part in a separate quarter called La Beurriere, in the upper part of the town. Boulogne and its en virons have foundries, cement factories, important steel-pen manu factories, oil works, dye-works, fish curing works, flax mills, saw mills, and manufactories of cloth, ropes, fireproof ware, chocolate, boots and shoes, and soap. Shipbuilding is also carried on. Boulogne is the seat of a sub-prefect, and has tribunals of first instance, and of commerce, a board of trade arbitrators and a chamber of commerce.