When were the Germans closest to Paris in World War 1?

The Germans were closest to Paris during World War I in September 1914, during the First Battle of the Marne. After a rapid advance through Belgium and northern France, German forces reached the outskirts of Paris, threatening the city. However, the Allied forces launched a counteroffensive, successfully pushing the Germans back and marking a significant turning point in the war. This battle effectively ended the German hopes of a quick victory in France.