The authorship and date of this map are enigmatic: the engraving has traditionally been attributed to 

. A contract between Crivelli and Francesco dal Pozzo dated 22 April 1474 obliged Crivelli to produce fifty copies of an unidentified world map. It has been suggested that this map and the one mentioned in the document are the same. However, stylistic differences between the maps in the Bologna 

' (1477) and this map that raises doubts they were made by the same engraver.

Three other copies of this map are known in the Newberry Library, Chicago, the John Carter Brown Library, Providence, and the Ashmolean Museum, Oxford. All are restrikes from the original plate made by Pietro de Nobili of Rome in the second half of the sixteenth century, possibly circa 1590. While each of these bears Nobili’s imprint, the example here lacks any printer’s mark, since the lower border is cut away. The watermark found on both leaves, a star surmounted by a cross can be dated to around 1580 and a Fabriano paper, or to 1479 and a Bologna paper. Though it is perhaps more likely from Nobili’s restrike, it remains possible that this map is an original copy.

This map represents the world as described in Ptolemy’s '

' and bears the hallmarks of other late fifteenth-century examples, which represent the world as known in the second century CE. The use of a conical projection acknowledges a spherical world, and and understanding that the map illustrates uninhabited or unknown regions. 

The map extends from Great Britain in the northwest, the Canary Islands in the West, mid-China in the East, and northern Africa in the South; the Indian Ocean features a large island, Taprobana (modern day Sri Lanka), lettered in Roman capitals. A large southern continent, 'Terra Australis', surrounds and land-locks the southern Indian Ocean. Allegorical personifications of ten cardinal winds among clouds surround the earth, framed by a scrolled border on the left.

 engraved map of the world on two half-sheets, joined.

This Ptolemaic map was printed in 1478 on a separately-issued broadsheet rather than as part of an atlas. The map is bounded by twelve curly-haired windheads who float amid the stars. The topography, seas, and rivers are richly depicted and the remnants of a filigree border decorates the left-hand edge of the sheet. 

Although the authorship of this map is generally attributed to celebrated engraver 

, there is no signature or printer's mark. Even the watermark in the paper is ambiguous. Thus, the map’s origins remain shrouded in mystery.

This map was engraved in Bologna in the late-fifteenth century, most likely by 

. Although the information conveyed is conventional to Ptolemy’s '

', the map has no direct model. Even its closest comparison, a Ptolemy atlas from 1477, has noticeable differences. The present map is generally richer in geographic details; for example, it shows additional branches of two Asian rivers, the 'Orchardes' and the 'Bantisus', both of which flow off the map at its north-eastern extremity. Over one hundred years after its creation, this map was restruck by the Roman printer Pietro de Nobili, testifying to the enduring legacy of Ptolemy’s work despite significant technological advances and geographic 'discoveries'. It also confirms the aesthetic appeal of this map. 

This is a well-preserved example of Crivelli’s map of the world, only known in four copies, with a distinguished provenance extending back to the early decades of the twentieth century.

A Ptolemaic World Map attributed to Taddeo Crivelli