Bar-sur-Seine is a commune in the Aube department in the Grand Est region of north-central France. In the middle ages it constituted the C…Bar-sur-Seine is a commune in the Aube department in the Grand Est region of north-central France. In the middle ages it constituted the Châtellenie de Bar-sur-Seine. The inhabitants of the commune are known as Barrois or Barroises and Barséquanais or Barséquanaises.