The De civitate Dei – a great and hard work (magnum opus et arduum), according to the statement by Augustine himself – is an articulated reply to the charges the Christians were brought to as being origin of the empire corruption, as well as cause of the sack of Rome in 410; but it is also, and above all, a theology of history, where the peculiar features of the civitas terrena and the civitas caelestis are set off against each other. The De civitate had an uninterrupted success, and humanists were particularly fond of its reading. The Guarnerianus ms. 8, copied in 1450, was recorded in the inventory in 1456, where, perhaps not by chance, it has the first place in the chest of «libri tuti indorati» (‘fully gilded books’); while in the inventory of 1461, in the section dedicated to the «Libri ecclesiastici» (‘Ecclesiastical books’) it is the second to be recorded immediately after the «Bibia in pergamenis deaurata» (the current Guarner. 284). Copied in littera antiqua script by an unidentified copyist of Venetian school to whom the Guarneriana ms. 5 (Jerome), ms. 23 (Lactantius), ms. 51 (Cesar) and ms. 92 (Svetonius) are to be ascribed, too, this codex shows a ‘tied neck-knot’ decoration that in Elisabetta Barile’s opinion should be to get ascribed to Andrea Contrario, an illuminator belonging to the above mentioned Francesco Barbaro. In the middle of the lower border on f. 19r there is the miniature of Guarnerio’s coat of arms.