the most famous prisoner in the fortress of arad was undoubtedly gavrilo princip, who on 28 june 1914 killed the heir to the throne of austria-hungary, archduke franz ferdinand and his wife, sophie, in sarajevo, which led to the outbreak of world war i. about the inhuman conditions in which prisoners were held in the fortress of arad warned ştefan cicio pop, deputy of the romanian national party in an interpellation to the hungarian parliament in budapest during 1917.