In 946 the castle of Château-Thierry was the home of Herbert le-Vieux, Count of Omois (Fr: comté d'Omois) of the House of Vermandois & Soissons.
Château-Thierry was the site of two important battles. The Battle of Château-Thierry (1814) in the Napoleonic Wars between France and Prussia, and Battle of Château-Thierry (1918) in World War I, between the United States and Germany.
In 1918 a mounting for the infamous Paris Gun was found near the castle. The cannon itself was never found