Biondo's greatest works were Italia illustrata (Italy Illuminated, written between 1448 and 1458, published 1474) and the Historiarum ab inclinatione Romanorum imperii decades (Decades of History from the Deterioration of the Roman Empire, written from 1439 to 1453, published in 1483).
The Italia illustrata (1474) is a geography, based on the author's personal travels, and history of fourteen Italian regions (regiones).