The son of a blacksmith, Dedue's family were from Duscur, a sparsely-populated independent region north-west of Fhirdiad. After the assassination of the Faerghus royal family, the people of Duscur rapidly became a scapegoat. The entire region was placed under House Kleiman's rule, and its residents were nearly eliminated. Dedue was saved by the Tragedy of Duscur's one survivor of nobility, Prince Dimitri, who he has sworn his life to in return.

While Dedue feels that his highest duty is to protect Dimitri, he enjoys preserving the memory of Duscur both through cooking and the cultivation of its flowers.