Over thousands of years, maps developed from two-dimensional rock art depicting constellations to Christianity-focused “T and O” maps depicting Jerusalem in the center of the map, to sophisticated three-dimensional views of the earth. According to James S. Aber, professor of geology at Emporia State University, the earliest known maps were made around 2300 BC on clay tablets. As time passed, philosophers developed greater knowledge of the Earth, and when Claudius Ptolemy, or "Ptolemy," was born, people understood the concept of a spherical earth rather than a flat earth. Ptolemy's map “depicted the Old World from about 60° N to 30° S latitude” (James S. Aber). After Ptolemy came the Middle Ages. During the medieval era the land on maps expanded and people drew TO maps, maps that have "Jerusalem... in the center and east... oriented toward the top of the map" (James S. Aber). Like Ptolemy, cartographers in the Middle Ages had a major influence on the development of maps. According to the powerpoint “The History of: Maps and Mapmaking,” “Ptolemy's maps sparked a sense of curiosity among the peoples of Europe and spurred new exploration” (San Jose Unified School District). Curiosity about Europe influenced two explorers to venture into unknown territories and make life-changing discoveries. The first of the two explorers, Christopher Columbus, traveled in 1492 in search of a trade route from Spain to Asia. According to the powerpoint Columbus used "Ptolemy's inaccurate maps" and, as a result of getting lost, made one of the best discoveries in history, the New World (SJUSD). The second explorer who significantly changed our world was Ferdinand Magellan. Magellan, like Columbus, was sent to find a trade route from Spain to Asia, but unlike Colonna…half of the map…he failed to create it. Although maps have developed from simple maps with east at the top to maps with depictions of different elevations, throughout history the primary goal of maps has been to help people better understand a topic. Works Cited Aber, James S. “History of Maps and Cartography.” History of Maps and Cartography. Np, ndWeb. 03 April 2014.San Jose Unified School District"The History of: Maps and Cartography." Types of maps." Geography 486. Np, nd Web. 03 April 2014. "Political map". Dizionario.com. Np, nd Web. 3 April 2014. "Topographic map". Dizionario.com. Np, nd Web. 3 April 2014. "Physical Map." World Atlas. Np, nd Web. 03 April 2014. "Types of Thematic Maps." Types of Thematic Maps. 03 April.2014.