Saint Omer and his friends came in the area to evangelize people... and they founded a little city and a wooden church, in 643. Destroyed by a fire in 1033, the brand new church was raised in the middle of the 11th century.
Bad luck... another fire destroyed the building in 1441! They decided to rebuild a new Gothic church, in 1370. In the beginning of the 15th century, they raised the nave. Later in 1572, the choir was completely altered.
Did you know this one had beautiful paving stone (13th century) on the soil? Unfortunately, canons replaced it by ordinary slabs in the 15th century...
We can see saint Erkembode's tomb, bishop of Thérouanne in the 7th century (a saint people invoke in order to cure rheumatism!) but also saint Omer's tomb (13th century). The huge organ dates back to 1717, made by Jean and Antoine Piette.