The novel opens with the 1900 Jubilee in Rome, at the height of the diatribe between the Vatican and the Italian state over the temporal power of the Church. Against this backdrop are the social claims of the time, animated by a Christian socialism with which Caine himself was imbued. Davide Rossi is a Leftist deputy who fights for the people and opposes a corrupt prime minister, who will try to prevent the crowning romance between Rossi and Donna Roma Volonna.
Caine lingered in Rome for a long time, visiting every place depicted in the novel; the descriptions of Regina Coeli, the Vatican and its ceremonies, the city's fashionable places and its squares teeming with ordinary people restore the climate of the time. The book is imbued with a religious sense of life, and the characters, even the most abject, are described compassionately, as a true investigator of the human soul. Reading this text more than a century after its release one cannot but be struck by the author's visionary ability: he foresaw for Italy, albeit in terms of "fantapolitics," the dictatorship, the abdication of the monarchy and the birth of the Republic, forty years in advance.
Thomas Henry Hall Caine (1853-1931) wrote some 15 novels, true best-sellers, which earned him the title "Sir" in 1917. The Isle of Sin (1894) is the best known of his works, thanks to A. Hitchcock's film adaptation in 1929. The Christian (1897) was the first book to sell one million copies in England. Pietro Mascagni set the stage version of The Eternal City to music in 1902.