Aim of this paper is to show that although "Il barone rampante" (1957) is a unique work in Calvino's narrative oeuvre, it nevertheless has many links with the narrative works that precede it as well as with the writer's future output. It starts by examining his earlier fiction that contains two brothers as protagonists, noting the influence on these of the classic novel that involves one good brother and one evil one, namely Stevenson's "Master of Ballantrae". Other 'roots' of the Baron are to be found in the classic works of world literature, particularly the great novels of the eighteenth and nineteenth centuries, from Defoe to Voltaire, Stendhal and Tolstoy. Finally the chapter investigates the relationship between "Il barone rampante" and autobiographical works such as "La speculazione edilizia" and "La strada di San Giovanni", and unearths connections even with postmodern works such as "Le città invisibili" and "Il castello dei destini incrociati". "Il barone" is thus a huge mosaic of world literature, and underneath the uniform surface of its text one can discern many traces of the works that precede and follow Calvino's longest novel.