The work was commissioned by the Holy Congregation for the Propagation of the Faith when Cavazzi returned from his first missionary trip to Angola in 1668.
Cavazzi probably began writing this work around 1660, perhaps in response to his witnessing the conversion of Queen Njinga to Christianity, which he regarded as something of a miracle.
This work, which is in the possession of the Araldi Family of Modena, Italy, was published in English translation on the internet by John Thornton, with a full introduction, and a comparison between this early manuscript and that of the eventual book.
Istorica descrizione de tre regni Congo, Matamba ed Angola.
Fra Giovanni Antonio Cavazzi da Montecuccolo: Documenti inediti Modena Thornton, John (1979).