page_title: Treaty of Tordesillas
section_title: Tordesillas meridian
hierarchical_section_title: Treaty of Tordesillas / Tordesillas meridian
caption_attribution_description: العربية: أحد أهم الخرائط الباقية من أوائل عصر الكشوف الجغرافية، خريطة العالم لكانتينو نسبةً إلى الوكيل الدبلوماسي الإيطالي ألبيرتو كانتينو في لشبونة الذي حصل على الخريطة عام 1502 من أجل دوق فيرارا. وقد نُسخت سراً دون تفويض. تشمل على كم كبير من المعلومات الجغرافية الجديدة مستندة على أربع رحلات بحرية: كولومبوس إلى الكاريبي، وبيدرو ألفاريز كابرال إلى البرازيل وفاسكو دي غاما تبعه رحلة كابرال إلى شرق أفريقيا والهند، ورحلة الأخوان كورت-ريل إلى جرينلاند ونيوفنلند. كانت جميع هذه الرحلات قد أبحرت تحت العلم البرتغالي باستثناء رحلة كولومبس. English: The most important manuscript map surviving from the early Age of Discovery, the Cantino World Map is named for Alberto Cantino, an Italian diplomatic agent in Lisbon who obtained it in 1502 for the Duke of Ferrara. It was covertly copied without authorization. It incorporates extensive new geographical information based on four series of voyages: Columbus to the Caribbean, Pedro Álvarez Cabral to Brazil, Vasco de Gama followed by Cabral to eastern Africa and India, and the brothers Corte-Real to Greenland and Newfoundland. Except for Columbus, all had sailed under the Portuguese flag.
context_page_description: The Treaty of Tordesillas, signed at Tordesillas in Spain on June 7, 1494, and authenticated at Setúbal, Portugal, divided the newly-discovered lands outside Europe between the Portuguese Empire and the Spanish Empire, along a meridian 370 leagues west of the Cape Verde islands, off the west coast of Africa. That line of demarcation was about halfway between the Cape Verde islands and the islands entered by Christopher Columbus on his first voyage, named in the treaty as Cipangu and Antilia.
  The lands to the east would belong to Portugal and the lands to the west to Castile. The treaty was signed by Spain, 2 July 1494, and by Portugal, 5 September 1494. The other side of the world was divided a few decades later by the Treaty of Zaragoza, signed on 22 April 1529, which specified the antimeridian to the line of demarcation specified in the Treaty of Tordesillas. Originals of both treaties are kept at the General Archive of the Indies in Spain and at the Torre do Tombo National Archive in Portugal.
context_section_description: The Treaty of Tordesillas only specified the line of demarcation in leagues from the Cape Verde Islands. It did not specify the line in degrees, nor did it identify the specific island or the specific length of its league. Instead, the treaty stated that these matters were to be settled by a joint voyage which never occurred. The number of degrees can be determined via a ratio of marine leagues to degrees applied to the Earth regardless of its assumed size, or via a specific marine league applied to the true size of the Earth, called "our sphere" by historian Henry Harrisse.
  The earliest Aragonese opinion was provided by Jaime Ferrer in 1495 at the request of the Aragonese king and Castilian queen to those monarchs. He stated that the demarcation line was 18° west of the most central island of the Cape Verde Islands, which is Fogo according to Harrisse, having a longitude of 24°25′ west of Greenwich, hence Ferrer placed the line at 42°25′W on his sphere, which was 21.1% larger than our sphere. Ferrer also stated that his league contained 32 Olympic stades, or 6.15264 km according to Harrisse, thus Ferrer's line was 2,276.5 km west of Fogo at 47°37′W on our sphere.
  The earliest surviving Portuguese opinion is on the Cantino planisphere of 1502. Because its demarcation line was midway between Cape Saint Roque (northeast cape of South America) and the mouth of the Amazon River (its estuary is marked Todo este mar he de agua doçe—"All of this sea is fresh water"—and its river is marked Rio grande, "great river"), Harrisse concluded that the line was at 42°30′W on our sphere. Harrisse believed the large estuary just west of the line on the Cantino map was that of the Rio Maranhão (this estuary is now the Baía de São Marcos and the river is now the Mearim), whose flow is so weak that its gulf does not contain fresh water.
  In 1518 another Castilian opinion was provided by Martin Fernandez de Enciso. Harrisse concluded that Enciso placed his line at 47°24′W on his sphere (7.7% smaller than ours), but at 45°38′W on our sphere using Enciso's numerical data. Enciso also described the coastal features near which the line passed in a very confused manner. Harrisse concluded from this description that Enciso's line could also be near the mouth of the Amazon between 49°W and 50°W.
  In 1524 the Castilian pilots (ships' captains) Thomas Duran, Sebastian Cabot (son of John Cabot), and Juan Vespuccius (nephew of Amerigo Vespucci) gave their opinion to the Badajoz Junta, whose failure to resolve the dispute led to the Treaty of Saragossa. They specified that the line was 22° plus nearly 9 miles west of the center of Santo Antão (the westernmost Cape Verde island), which Harrisse concluded was 47°17′W on their sphere (3.1% smaller than ours) and 46°36′W on our sphere.
  In 1524 the Portuguese presented a globe to the Badajoz Junta on which the line was marked 21°30′ west of Santo Antão (22°6′36″ on our sphere).
caption: Cantino planisphere depicting the meridian, 1502
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