The River Marne, which rises on the plateau of Langres at Balesme-sur-Marne (Marne) and joins the River Seine at Charenton-le-Pont (Val-de-Marne), was anciently called Matrona, as Caesar in De Bello Gallico (Book I, 1) mentions.1851
The word evolved into Materna in 632, Matrena around 700, Maderna in 1158, Marna in 1185 and Marne in 1281. See Nègre, 1990, p. 119, n° 2179.