The bulls of Nicholas V and his successors made no further mention of the "Donation", even when partitioning the New World, though the doctrine of "omni-insular" papal fiefdoms, developed out of the "Donation"'s vague references to islands since Pope Nicholas II's grant of Sicily to Robert Guiscard, was deployed after 1492 in papal pronouncements on the overlapping claims of the Iberian kingdoms in the Americas and Moluccas, including "Inter caetera", a bull that resulted in the Treaty of Tordesillas and the Treaty of Zaragoza. Valla's treatise was taken up vehemently by writers of the Protestant Reformation, such as Ulrich von Hutten and Martin Luther, causing the treatise to be placed on the index of banned books in the mid-16th century. The "Donation" continued to be tacitly accepted as authentic until Caesar Baronius in his "Annales Ecclesiastici" (published 1588–1607) admitted that it was a forgery, after which it was almost universally accepted as such. Some continued to argue for its authenticity; nearly a century after "Annales Ecclesiastici", Christian Wolff still alluded to the "Donation" as undisputed fact.