Marne is a department in the Grand Est region of France. It is named after the river Marne which flows through it. The prefecture of Marne is Châlons-en-Champagne. The subprefectures are Épernay, Reims, and Vitry-le-François. It had a population of 566,855 in 2019. The Champagne vineyards producing the eponymous sparkling wine are in Marne.