At Saint-Omer begins the canalised portion of the Aa River, which reaches the English Channel at Gravelines[?], and under its walls it connects with the Neuffossé canal, which ends at the Lys[?]. The fortifications were demolished during the last decade of the 19th century and boulevards and new thoroughfares made in their place. There are two harbours outside and one within the city. Saint-Omer has wide streets and spacious squares, but little animation.
The old cathedral belongs almost entirely to the 13th, 14th and 15th centuries. A heavy square tower finished in 1499 surmounts the west portal. The church contains interesting paintings, a colossal statue of Christ seated between the Virgin and St John (13th century, originally belonging to the cathedral of Thérouanne and presented by the emperor Charles V, Holy Roman Emperor), the cenotaph of Saint-Omer (13th century) and numerous ex-votos. The richly decorated chapel in the transept contains a wooden figure of the Virgin (12th century), the object of pilgrimages. Of St Bertin, the church of the abbey (built between 1326 and 1520 on the site of previous churches) where Childeric III retired to end his days, there remain some arches and a lofty tower, which serve to adorn a public garden, Several other churches or convent chapels are of interest, among them St Sepulchre (14th century), which has a beautiful stone spire and stained-glass windows.
A fine collection of records, a picture-gallery, and a theatre are all accommodated in the town hall, built of the materials of the abbey of St Bertin. There are several houses of the 16th and 17th centuries; of the latter the finest is the Hôtel Colbert, once the royal lodging, and now occupied by an archaeological museum. Among the hospitals the military hospital is of note as occupying the well-known college opened by the English Jesuits in 1592. The old episcopal palace adjoining the cathedral is used as a court-house. The chief statue in the town is that of Jacqueline Robin.
Saint-Omer is the seat of a court of assizes, of tribunals of first instance and of commerce, of a chamber of commerce, and of a board of trade arbitration. Besides the lycée, there are schools of music and of art.
The industries include the manufacture of linen goods, sugar, soap, tobaccopipes, and mustard, the distilling of oil and liqueurs, dyeing, salt-refining, malting and brewing. The suburb of Haut Pont to the north of Saint-Omer is inhabited by a special stock, which has remained faithful to the Flemish language, its original costume and its peculiar customs, and is distinguished by honesty and industry. The ground which these people cultivate has been reclaimed from the marsh, and the lègres (square blocks of land) communicate with each other only by boats floated on the ditches and canals that divide them. At the end of the marsh, on the borders of the forest of Clairmarais, are the ruins of the abbey founded in 1140 by Thierry d'Alsace, to which Thomas Becket betook himself in 1165. To the south of Saint-Omer, on a hill commanding the Aa, lies the camp of Helfaut, often called the camp of Saint-Omer. On the Canal de Neuf-Fessé, near the town, is the Ascenseur des Fontinettes, a hydraulic lift enabling canal boats to surmount a difference of level of over 40 feet.
Omer, bishop of Thérouanne, in the 7th century established the monastery of St Bertin, from which that of Notre-Dame was an offshoot. Rivalry and dissension, which lasted till the Revolution, soon sprang up between the two monasteries, becoming especially virulent when in 1559 St Omer became a bishopric and Notre-Dame was raised to the rank of cathedral.
In the 9th century the village which grew up round the monasteries took the name of St Omer. The Normans laid the place waste about 860 and 880, but ten years later found town and monastery surrounded by walls and safe from their attack.
Situated on the borders of territories frequently disputed by French, Flemish, English and Spaniards, St Omer long continued subject to siege and military disaster. In 1071 Philip I and Count Arnulf III of Flanders[?] were defeated at St Omer by Robert the Frisian. In 1127 the town received a communal charter from William Clito, count of Flanders. In 1493 it came to the Low Countries as part of the Spanish dominion. The French made futile attempts against it between 1551 and 1596, and again in 1638 (under Cardinal Richelieu) and 1647. But in 1677, after seventeen days' siege, Louis XIV forced the town to capitulate; and the peace of Nijmegen[?] permanently confirmed the conquest. In 1711 St Omer, on the verge of surrendering to Prince Eugene of Savoy and Marlborough owing to famine, was saved by the daring of Jacqueline Robin, who risked her life in bringing provisions into the place. St Omer ceased to be a bishopric in 1801.