Wisques Clety Sunday Street Market La Chapelle de Nielles les Thérouanne L'Église Saint Martin Archaeological Museum Thérouanne. Capital of the Belgian Moroni tribe (638). Wealthiest bishopric in Northern France. Finest Gothic cathedral in Northern France (12 C.). Entire city razed in 1553 by Spain's Charles V in retaliation for a battle lost to the French.... Continue Reading →