Introduction of Saint-Omer
City of Pas-de-Calais department, in Fland ers, on the Aa River, 22 mi SE of Calais. It developed arounda seventh-century monastery founded by St. Omer,bishop of Therouanne, whose tomb is now enclosedwithin the basilica of Notre Dame. During the ninthcentury the Flemish built a fort and walled settlementhere. During the later Middle Ages, with its abbey ofSt. Bertin, now in ruins, it was a famous center oflearning and also of the Flemish wool trade withEn gland . It did not become part of France until1677, when Louis XIV annexed it after a long historyof sieges. During World War I it was one of the principalheadquarters of the British army, and it washeavily bombed and shelled in both world wars.