Swenheym (and Arnold Pannartz) introduced the printing press to Italy at the height of the Renaissance, having been apprenticed to Guttenberg. Initially, under the enthusiastic patronage of Pope Paul II, Swenheym concentrated on publishing texts, but he later turned to producing the first illustrated Cosmographia in the early 1470s when enthusiasm was not sustained by the Pope's successor, Sixtus IV. The work was ultimately published one year after Swenheym's death in 1477. The plates for the 1478 Rome Ptolemy were later purchased by Petrus de Turre in 1490, who published the second edition of the map. Until the 1477 edition was definitively dated, the 1478 edition was believed to be the first printed atlas. It was printed by Arnoldus Buckinck, and is thought to be the only known book with his imprint. Buckinck completed the work started by Conrad Sweynheym, whose method of using a printing press for the copperplate maps, together with the fine engraving, produced an excellent result. The text was edited by Domitius Calderinus of Verona; he collated various Latin manuscripts in the translation by Jacobus Angelus, with an ancient Greek Manuscript, which had been amended by Geirgius Gemistus (d. 1450). Calderinus was a careful worker, and his edition had been much admired for the correctness of the text, the fine typography, and the brilliant engraving. Christopher Colombus owned a copy of this edition, which he annotated. The run of the edition is not known, but it is considered to be scarce and is therefore rare and important. Conrad Swehnheym's 1478 edition of Ptolemy's work is also of tremendous importance as the first set of maps to employ the "punched letter" printing process. As noted by Tony Campbell, "The development of lettering and numeral punches in fifteenth-century Italy, as a semi-mechanical alternative to the engraver's burin, marks a little-known point of contact between the histories of engraving and cartography. One of the unique features of a map is its necessarily dense toponymy, requiring the time-consuming skills of an experienced lettering engraver. Very early in the history of printed maps, indeed during the preparation of the first set of maps to be engraved (if not quite the first to be published), punching was devised as a labor-saving alternative." "Conrad Sweynheym does not expressly claim responsibility for inventing punched lettering. But the dedication to the 1478 Rome edition of Ptolemy's Cosmographia (or Geographia), which appeared the year after his death, referred to the three years (i.e. 1474-77) during which, 'calling on the help of mathematicians, he gave instruction in the method of printing [the maps] from copper plates'. On this passage and the evidence of the engraved maps which Arnoldus Buckinck issued after Sweynheym's death, hangs the German-born printer's claim to a technique that would be used fairly widely on Italian maps for the next century or more." Conrad Swenheym (Mainz), is widely thought to have been present at the birth of printing while an apprentice of Johann Guttenberg. After Mainz was sacked in 1462, Swenheym fled south to Italy and arrived at the Benedictine Monastery of Subiaco, at the suggestion of the great humanist and cartographer Cardinal Nicholas of Cusa. In 1464-5, Swenheyn and Arnold Pannartz introduced the first printing press to Italy. Over the next few years, Pope Paul II was to become so enthusiastic about the new medium that he liquidated scriptoria and commissioned several newly established printers to publish vast quantities of religious and humanist texts. In 1467, Swenheym and Pannartz moved to Rome under the Pope's patronage where they printed over fifty books from their press at the Massimi Palace. Unfortunately, when the pope died in 1471, the new pontiff Sixtus IV disavowed the numerous unpaid orders of his predecessor. Swenheym and Pannartz elected to refocus their efforts on to creating the first printed illustrated edition of Ptolemy's Cosmographia, By 1474, Swenheym is recorded as having trained "mathematicians" to engrave maps on copper. Unfortunately, he did not survive to see the book's publication, but his contribution to the history of printing and map-making places him at the highest level of importance in the evolution of the printed map. The 1478 and 1490 editions are identical, although there are different watermarks in the paper. There is some debate as to whether the watermarks are in fact completely reliable in determining the editions.