Marie Pierre Louis Hélie de Talleyrand-Périgord, 5th Duke of Talleyrand and Dino, Prince, then Duke of Sagan, was a French socialite and son of Boson de Talleyrand-Périgord.

The Duchy of Żagań or Duchy of Sagan was one of the duchies of Silesia ruled by the Silesian Piasts. Its capital was Żagań in Lower Silesia, the territory stretched to the town of Nowogród Bobrzański in the north and reached the Lusatian Neisse at Przewóz in the west, including two villages beyond the river.