This magnificent chart is from the first edition of Sir Robert Dudley’s landmark ‘Arcano del Mare’ published in Florence, 1646-48. Lord Wardington wrote that it is “ONE OF THE GREATEST ATLASES OF THE WORLD and one of the most complex ever produced: it is the first sea-atlas of the whole world; the first with all the charts constructed using Mercator’s new projection, as corrected by Edward Wright; the first to give magnetic declination; the first to give prevailing winds and currents; later to be further expanded by Maury and J.T. Towson in the nineteenth century; the first to expound the advantages of ‘Great Circle Sailing’; and the first sea-atlas to be compiled by an Englishman, albeit abroad in Italy” (Lord Wardington, “Sir Robert Dudley”, The Book Collector, 52 (2003). This particular chart is of note because it is one of only two in the atlas to be so highly decorated. This was the only region of the world in which Dudley had particular experience and knowledge. It covers the area from Guiana to the mouth of the Amazon River. In 1594 he led an expedition to the Orinoco and Guiana. The charts are decorated with images of natives and animals. He supplied Robert Thornton with charts for his voyage in the ‘Santa Lucia’ to the Amazon in 1607-08. In return Thornton supplied Dudley with information. The result is a surviving manuscript chart in the Bayerische Staatsbibliothek, Munich (ill. Imago Mundi). It is from this chart updated with information of the mouth of the Amazon itself by Johannes de Laet in 1625 that this printed map is derived. Dilke ‘Sir Robert Dudley’s Contributions to Cartography’, in ‘The Map Collector’ no. 19 pp. 10-14; Tyacke ‘English Charting of the River Amazon c.1595-c.1630’ in Imago Mundi 32 pp. 73-89 Fig. 4 & note 4.