Saint-Omer is a commune in France.
The canalised portion of the river Aa begins at Saint-Omer, reaching the North Sea at Gravelines in northern France. Below its walls, the Aa connects with the Neufossé Canal, which ends at the Lys River.
Saint-Omer first appeared in the writings during the 7th century under the name of Sithiu (Sithieu or Sitdiu), around the Saint-Bertin abbey founded on the impulsion of Audomar (Audomarus, Odemaars or Omer).
Omer, bishop of Thérouanne, in the 7th century established the Abbey of Saint Bertin, from which that of Notre-Dame was an offshoot. Rivalry and dissension, which lasted till the French 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 that grew up round the monasteries took the name of St Omer. The Normans laid the place waste about 860 and 880. Ten years later the town and monastery had built fortified walls and were 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 invasions. 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 1340 a large battle was fought in the town's suburbs between an Anglo-Flemish army and a French one under Eudes IV, Duke of Burgundy, in which the Flemish force was forced to withdraw. In 1493 the town became part of the Low Countries and under Spanish dominion for more than 170 years. King Henry VIII of England employed a swordsman from Saint-Omer for the execution of Queen Anne Boleyn, rather than having a queen consort beheaded with the common axe.
The French made futile attempts against the town between 1551-96. During the Thirty Years' War, the French attacked in 1638 (under Cardinal Richelieu) and 1647. Finally in 1677, after seventeen days' siege, Louis XIV forced the town to capitulate; and the peace of Nijmegen permanently confirmed the conquest and its annexation by France. In 1711 St Omer, on the verge of surrendering because of famine, was saved by the daring of Jacqueline Robin, who risked her life to bring provisions into the town.
The College of Saint Omer was established in 1593 by Fr Robert Persons SJ, an English Jesuit, to educate English Catholics. After the Protestant Reformation, England had established penal laws against Catholic education in the country. The college operated in St Omer until 1762, when it migrated to Bruges and then to Liège in 1773. It finally moved to England in 1794, settling at Stonyhurst, Lancashire. Former students of the College of Saint Omer include John Carroll, his brother Daniel and his cousin Charles.
During World War I on 8 October 1914, the British Royal Flying Corps (RFC) arrived in Saint-Omer and a headquarters was established at the aerodrome next to the local race course. For the following four years, Saint-Omer was a focal point for all RFC operations in the field. Although most squadrons only used Saint-Omer as a transit camp before moving on to other locations, the base grew in importance as it increased its logistic support to the RFC. Many Royal Air Force squadrons can trace their roots to formation at Saint-Omer during this period. Among which are No. IX Squadron RAF which was formed at Saint-Omer, 14 December 1914 and No. 16 Squadron RAF which was formed on 10 February 1915.
During World War II, the Luftwaffe used the airfield. When the RAF's legless Battle of Britain ace, Douglas Bader, parachuted from his Spitfire during an aerial battle over France, he was initially treated at a Luftwaffe hospital at Saint Omer. He had lost an artificial leg when bailing out, and the RAF dropped him another one during a bombing raid.