In the early 12th century,
Saint-Omer was an important port in western
Flanders. Silting gradually cut it off from the
North Sea, resulting in the construction of a canal to the new coast at what is now Gravelines. The name is derived from the
Dutch Gravenenga, meaning Count's Canal. The new town became heavily fortified as it guarded the western borders of
Spanish territory in Flanders. Gravelines was taken by
Henry le Despenser's English forces during the
Norwich Crusade of 1383 and was that year destroyed on his orders as the English retreated towards Calais. There was a famous meeting at Gravelines in 1520, between the
Holy Roman Emperor Charles V and
Henry VIII of England. There were
two battles fought nearby:
the first was a land battle in 1558 resulting in a victory by Spanish forces of
Lamoral, Count of Egmont over the
French under Marshal
Paul des Thermes, while
the second was a naval attack using
fire ships in 1588 launched by England's
Royal Navy under
Lord Howard against the
Spanish Armada at
anchor. Gravelines was also the setting for
Sir Philip Sidney's failure to deliver the town from Spanish occupation in July 1586, which is described in the anonymous
A Discourse of the enterprise of Gravelines. The town was captured and recaptured several times by the French and Spanish between 1639 and 1658. It was finally annexed to France in the
Treaty of the Pyrenees of 1659. Only in the 19th century did the population become entirely French-speaking. On 24 May 1940, during the
Fall of France, German field marshal
Gerd von Rundstedt, commanding
Army Group A, ordered his armoured divisions to close up the "Canal Line" of
Lens-Gravelines, and halt there. ==Population==