[2][3][4] The premise of the work is the medieval European legend of a woman named Joan who ascended the church hierarchy and allegedly assumed the papal throne disguised as a man (sometimes identified as Pope John VIII) during the late 9th century.

[4] She elopes with a young monk named Frumentius, with whom she is involved romantically and resides (disguised as a man called "John") in a monastery in Fulda, Germany; they later go on to share many adventures travelling around Western Europe.

Intrigued by the story, he did extensive research in Germany, Italy, and finally the National Library of Greece, and collected significant material on the period in which the storyline takes place.

[1][8] As emphasized by the subtitle "medieval study", the author asserted the novel contained evidence that Pope Joan truly existed and that the Catholic Church had been attempting to cover up the fact for centuries.

[9] In his long introduction, he listed a number of spokesmen in favour of the legend and declared his attempt to provide a "delineation of the state of religion, as well as of the customs and traditions of the 9th century".

Rhoides responded to criticism by the Church initially with satirical commentaries on the press, followed –on a more serious tone– by the piece "A few words in response to the aphoristic circular of the Synod".