De Administrando Imperio
According to "De Administrando Imperio" (948–952), in chapter 35, "Diokleia" (Διόκλεια) included the "large, inhabited cities" of Gradetai, Nougrade, and Lontodokla. Gradetai may have been Starigrad, Nougrade may have been Prevlaka, while the location of Lontodokla is uncertain.