The story of Catiline, the Roman noble who plotted to overthrow the Roman Republic in 63 B.C., occupies a significant place in Florentine historiography and political thought of the later Middle Ages and early Renaissance. Starting with theChronica de origine civitatis (ca. 1228), this article traces the sources of the medieval account back to the ancient epitomes and investigates its relation to Sallust’sBellum Catilinae. It then describes the two branches or traditions of the story that developed in the course of the thirteenth and fourteenth centuries: (1) the classical or civic, which centered on the figure of Catiline-the-villain, rebel and enemy of Rome (and of Rome’s daughter-city Florence) and (2) the feudal or chivalric, which recounted the legendary adventures of Catiline-the-knight, protector of Fiesole, the rival of Florence. In the final sections of the article, attention focuses on the success of the classical version of the story, linked to Guelfambienti and, in turn, to the growth of a conservative republican ideology. While the celebration of Roman civic virtues, summed up in Cicero’s defense of theres publica against the rebel Catiline, legitimated and ennobled the claims of the rising merchant and banking families, the vilification of Catiline as public enemy provided effective propaganda against new challenges from lower-class movements. Continuously present in the elaboration of Florentine “civic humanism,” Sallust’s story of Catiline supplies, in fact, an important connection between Guelf patriotism and the classicizing republicanism of the Quattrocento.1
