DIEPPE, a seaport of northern France, capital of an arron dissement in the department of Seine-Inf erieure, on the English Channel, 38 m. N. of Rouen, and 1o5 m. N.W. of Paris by the Western railway. Pop. (1931) 24,236. It is suggested that Dieppe owed its origin to Norman adventurers, who found its "diep" or inlet suitable for their ships, but it was unimportant till the late 12th century. Its first castle was probably built in 1188 by Henry II. of England, and Philip Augustus attacked it in In 1197 it was bestowed by Richard I. of England on the arch bishop of Rouen in return for territory near the latter city. In it was plundered by the English, but it soon recovered, and, in spite of opposition from the lords of Hantot, fortified itself. Its commercial activity was already great, and it is believed that its seamen visited the coast of Guinea in 1339, and founded there a Petit Dieppe in 1365. The town was occupied by the English from 1420 to 1435. A siege undertaken in 1442 by John Talbot, first earl of Shrewsbury, was raised by the dauphin, afterwards Louis XI., and the day of the deliverance continued for cen turies to be celebrated by a great procession and miracle plays. In the beginning of the 16th century Jean Parmentier, a native of the town, made voyages to Brazil and Sumatra; and a little later its merchant prince, Jacques Ango, was able to blockade the Portuguese fleet in the Tagus. Francis I. began improvements, continued under his successor. Its inhabitants in great number embraced the reformed religion; and they were among the first to acknowledge Henry IV., who fought one of his great battles at the neighbouring village of Arques. Few cities suffered more from the revocation of the edict of Nantes in 1685; and this blow was followed in 1694 by a terrible bombardment on the part of the English and Dutch. The town was rebuilt after the peace of Ryswick, but its modern prosperity dates only from the 19th century, partly owing to Marie Caroline, duchess of Berry, who brought it into fashion as a watering-place; and also because the railway gave an impetus to its trade. During the Franco-German War the town was occupied by the Germans from December 1870 till July 1871. It stands at the mouth of the river Arques in a valley bordered on each side by steep white cliffs. The main part of the town lies to the west, and the fishing suburb of Le Pollet to the east of the river and harbour. The sea-front of Dieppe, which in summer attracts large numbers of visitors, consists of a pebbly beach backed by a handsome marine promenade. Dieppe, has a modern aspect and two squares side by side and immediately to the west of the outer harbour form the nucleus of the town. The church of St. Jacques, founded in the 13th century, consists largely of later workmanship and was restored in the i9th century. The castle, overlooking the beach from the summit of the western. cliff, was built in 1435. The church of Notre-Dame de Bon Secours on the opposite cliff, and the church of St. Remy, of the I6th and I7th centuries, are noteworthy. A well-equipped casino stands on the sea-front. The public institutions include the subprefecture, tribunals of first instance and commerce, a chamber of commerce and a school of navigation.
Dieppe has one of the safest and deepest harbours on the English Channel. A curved passage cut in the bed of the Arques and protected by an eastern and a western jetty gives access to the outer harbour, which communicates at the east end by a lock gate with the Bassin Duquesne and the Bassin Berigny, and at the west end by the New Channel, with an inner tidal harbour and two other basins. Vessels drawing 20 ft. can enter at neap tide. A dry-dock and a gridiron are among the repairing facilities of the port. The harbour railway station is on the north-west quay of the outer harbour. The distance of Dieppe from New haven, with which there has long been daily communication, is 64 m. The imports include silk and cotton goods, thread, oil seeds, timber, coal, iron, patent fuel cement, china-clay, machinery, tobacco and mineral oil; leading exports are wine, silk, woollen and cotton fabrics, vegetables and fruit and flint-pebbles. The industries comprise shipbuilding, oil-refining, steam-sawing, the manufacture of machinery, rope, porcelain, briquettes, and articles in ivory and bone, the production of which dates from the 15th century. The fishermen of Le Pollet, traditionally of Venetian origin, are among the main providers of the Parisian market. The sea-bathing attracts many visitors in the summer. Two miles to the north-east of the town is the ancient camp known as the Cite de Limes, which perhaps furnished the nucleus of the population of Dieppe.
See L. Vitet, Histoire de Dieppe (Paris, 1844) ; D. Asseline, Les Antiquites et chroniques de la ville de Dieppe, a 17th-century account published at Paris in 1874.