This is the first and only issue of Michael Tramezzino’s double-hemisphere map making it extremely rare. Shirley (2001) estimates there are less than a dozen known examples.

Tramezzino’s other cartographic works are more common and often preserve copies of now lost wall maps such as those of Jan van Deventer, which depict the provinces of the Low Countries. Unfortunately, because of the vulnerability of wall maps, it is often only through Tramezzino's copies, albeit on a much-reduced scale, that evidence of van Deventer's original work is preserved. Indeed, when 

, the Antwerp publisher, active from the 1550s to the 1590s, wanted to publish maps of the constituent provinces of the Low Countries, he turned to Tramezzino's version as a source in the absence of van Deventer's original.

This sheet shows the Western Hemisphere of Tramezzino’s double hemisphere map. It pairs with a second sheet showing the Eastern Hemisphere also in the Sunderland Collection (see SC-TM-1554-Tramezzino-HemisphereMapE). 

The Western Hemisphere is centred on the Pacific Ocean, showing North and South America with California as a peninsula; the Eastern Hemisphere is centred on Africa. Each hemisphere has letterpress in the neatline acknowledging printing privileges from the Papacy and the Venetian Senate (‘Cum Privilegio Summi Pont et Senat. Venet. Michaelis Tramezini Formis M. D. LIIII Julius De Musis Venet In Aes Incidit M. D. LIIII’). Degrees of latitude and longitude also appear, as do compass directions, and little fleurons; the map shows the equator and tropics of Cancer and Capricorn, as well as horizontal and vertical meridians based on Roger Bacon’s projection. The oceans are decorated with beautiful galleons and other regional sailing ships. 

In the Western Hemisphere, North America and Asia are separated as in 

’s 1538 prototype, but details of the west coast and the Californian peninsula have been inserted. The serpentine east-west course of the Amazon is prominent, as is the exaggerated estuary of the River Plate; both are features which appeared on Sebastian Cabot’s map of 1544. However, unlike Cabot, an extensive southern continent has been added. This is in fact not a complete polar land mass but an extenuated island strip reaching across three-quarters of the circumference and leaving open sea to the south.

Michael Tramezzino (fl. 1526–1571) opened a publishing house in 1526 in Rome with his brother Francesco (fl. 1526–d. 1576). The pair relocated a year later to Venice following the sack of Rome by the troops of Charles V. The following year, Francesco returned to Rome, leaving Michael to open his shop in Venice. After this the brothers would occasionally collaborate. 

Tramezzino specialised in publishing maps not only from original sources but also reduced versions of maps originating outside Italy. It is often only through Tramezzino's smaller copies that some of the great and elusive wall maps of the era are known. He worked with a number of engravers of the Lafreri School, including Jacobus Bossius Belga (fl. 1555–1561) who engraved many of Tramezzino's copies of Deventer's work; Pirro Ligorio (fl. 1552–1563) who was an architect, artist, and cartographer born in Naples, but based in Rome; Sebastian de Re (fl. 1557–1562), who engraved for Tramezzino and published a few maps and plans under his own name.

This large map consists of two hemispheres, each printed from separate copper plates. The hemispheres are upon a ‘homolographic’, or evenly drawn meridian, projection first described by Roger Bacon in the thirteenth century. The map is beautifully engraved by Guilio de’ Musi of Venice, and although both his and Michael Tramezzino’s names are mentioned in the work, no cartographer is named.

This large map is the masterwork of Michael Tramezzino and forms a pair with a map of the Eastern Hemisphere also in the Sunderland Collection. Each map was printed from two copper plates to accommodate its scale. They are exquisitely engraved and technically superb.

This Western hemisphere map centres on the Pacific Ocean. The stippled oceans contain finely rendered ships, and the land masses are filled with place names and geographical features such as mountains, rivers, and lakes. The map is dedicated to Pope Julius III.

An exceptionally rare survival of this large world map. Shirley calls it “a masterpiece of Renaissance cartography without any obvious source, or indeed, any imitators”. An exceedingly rare and important map of the two hemispheres, and the single greatest achievement of the publisher Michael Tramezzino.

Engraved homolographic double-hemisphere map on two sheets, each printed from two copperplates 

Western Hemisphere of Tramezzino's Double Hemisphere Maps