Bishopric of Saint-Omer
Notre-Dame Cathedral at Saint-Omer
The diocese of Saint-Omer is a former Roman Catholic diocese in France. It goes back to the diocese of Thérouanne, which has existed since the 6th century . This was lifted in 1537 after Charles V had devastated Thérouanne and made it uninhabitable. The diocese was divided into three new bishoprics with headquarters in Ypres , Boulogne and Saint-Omer. With the Concordat of 1801 , the diocese of Saint-Omer was dissolved; the diocese went up in the diocese of Arras . The diocese belonged to the ecclesiastical province of Cambrai .