The City of the Sun is a dialogue between «a Grandmaster of the Knights Hospitaller and a Genoese Sea-Captain,» The book describes a theocratic society where goods, women and children are held in common. It also resembles the City of Adocentyn in the Picatrix, an Arabic guide to magical town planning. In the final part of the work, Campanella prophesies – in the veiled language of astrology – that the Spanish kings, in alliance with the Pope, are destined to be the instruments of a Divine Plan: the final victory of the True Faith and its diffusion in the whole world.