Copperplate engraving, 250 x 250 mm. A fine, decorative antique version of the circular world map created by Andrea Bianco in 1436, held at the Biblioteca Marciana in Venice. It is considered the earliest extant cartographic work depicting the Portuguese discovery of Cape Verde. This copper-engraved version comes from the first Italian edition (1783) of *Saggio sulla nautica antica de' Veneziani* (Essay on the Ancient Navigation of the Venetians) by Vincenzio Antonio Formaleoni (1752–1797). The map is oriented with a 90-degree counter-clockwise rotation; North is to the left. The upper section of the map—depicting East Asia—shows Paradise, Gog and Magog, the Emperor Kublai Khan, and a wide array of mythical creatures. A sea route to the Indies via Africa is indicated, predating the discovery of this passage by Dias. The *ixola perlina* (Pearl Island) is located in the southeastern Indian Ocean. The map is a schematic "T-O" representation of the world: a circle (O) divided by a T-shape, illustrating a world surrounded by water and split into three continents—Asia, Europe, and Africa. The horizontal bar of the "T" symbolizes the Don River (flowing into the Black Sea) and the Nile River, which separate Asia from Europe and Africa. The vertical bar of the "T" typically represents the Mediterranean Sea, separating Europe from Africa. This symbolic representation was widespread during the Middle Ages and held religious significance: the "T" represented the Cross, while the "O" symbolized the world. Jerusalem is placed at the center of the map, reflecting its spiritual importance in medieval Christianity. T-O maps are often oriented with East at the top—where Asia is located, associated with the Garden of Eden or Paradise—while Europe and Africa are at the bottom. These medieval maps represent an innovation compared to works of Greco-Roman geography, incorporating new knowledge and theories—ranging from the accounts of medieval travelers like Marco Polo to the latest Portuguese discoveries. Depicted here are the Portuguese discoveries along the west coast of Africa; the Gulf of Guinea is drawn with reasonable accuracy, despite having been explored only recently. The southern tip of Africa extends further south than it does in earlier editions of Ptolemy. These medieval T-O maps embrace the theory that the known continents are surrounded by a single, continuous ocean—a concept supported by various ancient geographers and historians such as Strabo, Eratosthenes, Hecataeus of Miletus, and Herodotus, but rejected by Ptolemy. This 18th-century Italian edition of the map is one of the few surviving early facsimiles of medieval world maps and is quite rare on the market. It is an excellent specimen, showing traces of the original publisher's folds.