This atlas has been attributed to the important Portuguese cartographer, navigator, and illuminator Fernão Vaz Dourado (circa 1520−80), based on similarities between other maps by Vaz and illustrations in this manuscript. Vaz spent his last years in Portuguese Goa (present-day India) and is known to have produced seven brilliantly illuminated sea atlases between 1568 and 1580. His portolan charts belong to a class of late-16th-century cartographic masterpieces, which reflect the period’s rising demand for cartographic works that were both visually impressive and accurate for practical navigation. This atlas, dating from about 1576, consists of 17 illuminated maps, in addition to declination tables and cosmographic rules. Among the maps included are those of the southern tip of South America and the Straits of Magellan; the Caribbean and nearby parts of North and South America; the Atlantic coast of present-day Canada (Labrador) and the United States; Scandinavia, the British Isles, and the Baltic Sea; Europe; the eastern Mediterranean; West Africa; southern Africa; Brazil; the island of Madagascar and neighboring Mozambique; East Africa, the Arabian Peninsula, and India; China and Southeast Asia; and the Pacific coast of Mexico and Baja California. Place-names are in Latin. The atlas belonged to the royal collections of Palácio das Necessidades in Lisbon. King Don Luís and King Don Carlos both commissioned sketches and reproductions of the maps. The atlas became part of the collections of the National Library of Portugal after 1910. It was previously owned by a “Cavalheiro Ferron” (circa 1843), a member of the Société de Géographie, and by João Martens Ferrão de Castelo Branco (after 1847).