Originally written in Italian and published in 1988 as a part of a larger book on the reception of the figure of John the Baptist, John of the Mandaeans is the first and only attempt to analyze all written texts and oral testimonies that over the centuries have reached Western scholarship, originating from the Mandaean lore and its traditions. Rarely called “the Baptist” in Mandaean texts, since he did not create the preexisting Mandean baptismal rites, John is a figure whose importance grows over time. In times of conflicts, he became an ideal model able to counter the most important figures of all competing religions, especially Jesus Christ and, in the early Islamic era, Muhammad, while, in more recent times, as the older cousin of Jesus, he is a model of religious coexistence. The history of John is the history of Mandaeism.