It is impossible to tell how much of the content of these traditional biographies is fiction and how much is fact. Large parts clearly are mere deduction from Juvenal's writings, but some elements appear more substantial. Juvenal never mentions a period of exile in his life, yet it appears in every extant traditional biography. Many scholars think the idea to be a later invention; the "Satires" do display some knowledge of Egypt and Britain, and it is thought that this gave rise to the tradition that Juvenal was exiled. Others, however - particularly Gilbert Highet - regard the exile as factual, and these scholars also supply a concrete date for the exile: 93 AD until 96, when Nerva became emperor. They argue that a reference to Juvenal in one of Martial's poems, which is dated to 92, is impossible if, at this stage Juvenal was already in exile, or, had served his time in exile, since in that case, Martial would not have wished to antagonise Domitian by mentioning such a "persona non grata" as Juvenal. If Juvenal was exiled, he would have lost his patrimony, and this may explain the consistent descriptions of the life of the client he bemoans in the "Satires".