The local tradition attributes it to Theuderic IV, the penultimate Merovingian king, who was imprisoned by Charles Martel, without a reliable source. Château-Thierry is the birthplace of Jean de La Fontaine and was the location of the First Battle of the Marne and Second Battle of the Marne. The region of Château-Thierry (the arrondissement, to be exact) is called the country of Omois.