The impossible redemption of Aly del Marnegro, "true Turkish"

In 1624 the corsair Aly Rais was captured by Sicilian galleys. Brought to Palermo, the Inquisition suspected that il was dealing with a renegade Christian. After gathering numerous testimonies and locating its baptismal records, they formally accused him of being the Ferrarese Francesco Guicciardino, taken by corsairs as a child and brought to Tunis, where he embraced the Muslim religion, became captain of the galleys of Biserta, and preyed on Christian shipping. Against these accusation, Aly claimed to be "Turkish" by birth and hence beyond the jurisdiction of Holy Office. By examining sources of Madrid (the inquisitorial records), from Tunis (the correspondence between the leaders of the Regency and French consular documents), and from Palermo (the letters of the Deputation for the Ransoming of Captives and of Cardinal Giannettino Doria), it is possible to reconstruct the political and diplomatic negotiations over a failed ramson, which enables us to see the complex of interests in play, beyond the commercial and financial interests typical of the "economie de la rançon".