The Descrittione is in nine books, an introductory book and an appendix on rivers and fauna and flora, with seven books between, each describing a kingdom: the kingdoms of Marrakesh, Fez, Tlemcen and Tunis, and the regions of Numidia, the sub-Saharan regions, and Egypt. The work circulated in manuscript form for decades. It was in Ramusio's manuscript that Pietro Bembo read it and was astonished: "I cannot imagine how a man could have so much detailed information about these things", he wrote to a correspondent, 2 April 1545.
The book's importance stemmed from its accuracy at a time when the area was little known to Europeans, and its publication at precisely the moment when European power was on a collision course with the Ottoman Empire in the eastern Mediterranean and Eastern Europe, at the time that it was definitively on the rise in the western Mediterranean and West Africa.
The book was an enormous success in Europe, and was translated into many other languages, remaining a definitive reference work for decades (and to some degree, centuries) afterwards. In English it was served by John Pory, whose translation appeared in 1600 under the title A Geographical Historie of Africa, Written in Arabicke and Italian by Iohn Leo a More... in which form Shakespeare may have seen it and reworked hints in creating the title character of his Othello (ca. 1603).
A twentieth-century rediscovery of the originally-dictated manuscript revealed that Ramusio, in smoothing the grammar of Leo Africanus's text had coloured many neutral details, to make it more palatable to Christian European audiences; French and English translators added further embellishments. Modern translations which incorporate this manuscript are thus more true to the original.