appropriate language might be needed.
Around 1144, Roger commissioned al-Idrisi to produce what we might now call an atlas. King Roger II had a keen interest in the extent of his domains, which are shown at their maximum reach, in around 1150, drawn in the dark tint on our rendition of al-Idrisi’s world map. In Arabic the work was called Kitāb nuzhat al-mushtāq fī ikhtirāq al-āfāq or ‘Entertainment for He Who Longs to Travel the World’. Al-Idrisi had produced a collection of 70 detailed maps covering the known world, their orientation with south at the top. (If you look at al-Idrisi’s work on the internet, his maps are frequently upside down, with north at the top, to help the modern viewer.) The atlas became known as The Book of Roger, indicating the king’s important role in sponsoring the work. It was created following the Greek tradition, dividing the world into seven climes and moving from west to east, describing each clime in detail. Al-Idrisi referred extensively to previous Arabic geographers in his final compilation. He also relied on his own observations as well as collating the reports of contemporary travellers, many of whom, as you might expect, passed through the ports and towns of Roger’s kingdom, located as it was in the central Mediterranean. The work’s geographical accuracy, an improvement on Ptolemy’s gigantic contribution, corrected the interpretation of the Indian Ocean as enclosed by land and the form of the Caspian Sea, and determined the direction of major European rivers. Further details were added concerning China and Tibet far in the east. In Africa, the lakes near the Mountains of the Moon are shown as the source of the Nile, whose course is tracked to the Mediterranean. The Niger River is also shown, locating the trading city of Timbuktu on the edge of the known world.
The map’s style and draughtsmanship and the choice of colour are a joy to behold. They have a kind of rhythmic quality; to my eye there is a modern feel – perhaps David Hockney’s pool paintings are suggested. I could stare at them for hours. Among all the triumphs of cartographic design, a calculating mind was at work on this map, as al-Idrisi estimated the circumference of the earth to be some 22,900 miles, which was just 8 per cent off from a modern calculation.
Map 17. Muhammad al-Idrisi was a geographer and cartographer. For much of his life he lived in Palermo, Sicily, at the court of King Roger II.
Al-Idrisi’s work remained a standard for accuracy for almost 300 years after it was written. Geographers and travellers from Islamic traditions, such as Ibn Battuta, Ibn Khaldun and Piri Reis, were influenced by it in creating their own views of the world, while European explorers such as Vasco da Gama and Christopher Columbus also read his work in detail, thus shaping Christian tradition also.
Sometime just before October 1451, Cristoffa Combo was born in the Republic of Genoa, now part of modern Italy. In Italian, he was known as Cristoforo Colombo, the son of Domenico Colombo and Susanna Fontanarossa, weavers and people of the middling sort. They also had a cheese stand where young Cristoffa helped out. In 1473, Cristoffa was placed as an apprentice business agent for trading families in the port of Genoa. From there he made various voyages around Genoese holdings on the Mediterranean, which may have included a journey to Chios, a major Aegean island and trade centre, then under the control of the Republic of Genoa.
Three years later, in the spring of 1476, he served on a ship that formed part of a major Genoese convoy carrying valuable cargo to northern Europe. His particular ship was known to have docked in England, at Bristol, and also visited Galway, in Ireland. It is rumoured that in 1477, he reached Iceland. No doubt while in Iceland he would have heard rumours of Christian communities in Greenland and, indeed, of lands further to the west. In the late 1440s, the Pope had written to the Icelandic Christians concerning the welfare of their fellow believers further to the west in Greenland.
By the end of 1477, Cristoffa was known to have been on a Portuguese ship that sailed from Galway to Lisbon, Portugal. There, he met up with his brother, Bartolomeo, and together they continued trading on behalf of notable local families. Bartolomeo also worked in a cartographic workshop, which was another source of information for Cristoffa, now styled as Cristóbal Colón, who worked out of Lisbon from 1477 until mid-1485.
In 1479, Cristóbal married Filipa Moniz Perestrelo, a woman from a notable Portuguese family, and lived on Porto Santo Island in the Madeira group of islands. While Cristóbal was climbing the social ladder and somehow finding the time to learn his trade as a captain and navigator, events on the other side of the Mediterranean had changed the view of the world as seen from Lisbon. In 1453, the expanding Ottoman Empire had taken Constantinople and moved across the land route to Asia, making it much less accessible, especially for the Christian West. Meanwhile, Portugal and Spain were in the final phase of driving out the Moors from Granada, the last Islamic outpost on the Iberian Peninsula. This made the development of a new sea route around Africa to Asia much more important. Around 1470, Paolo dal Pozzo Toscanelli, a Florentine astronomer, proposed to King Alfonso V of Portugal a new route west from Portugal, which he said would be a quicker and more direct route to reach China, Japan and the Spice Islands (the Moluccas, a group of islands in what is now Indonesia), rather than the circuitous route around Africa. Alfonso rejected the idea and later King John II continued to develop the Portuguese route around Africa.
Meanwhile, Paolo dal Pozzo Toscanelli had been in correspondence with Cristóbal in 1474, proposing his westward route to the Indies. By this time, Cristóbal himself had amassed a considerable amount of his own information, including a number of maps, as well as practical experience of the Atlantic sea routes west of Portugal down to the Canaries, the Cape Verde islands and the nearby coastline of Africa. In his own studies, Cristóbal had learned from works by Ahmad ibn Muhammad ibn Kathir al-Farghani, also known as Alfraganus, who estimated that a degree of latitude around the equator represented 56.66 miles. However, Cristóbal did not realise that this was expressed in Arabic miles rather than the Roman miles that he regularly used in his navigations. Therefore, he created an error in his calculations, estimating the circumference of the earth at about 30,200 kilometres (18,765 miles), whereas the correct value should have been 40,000 kilometres (24,855 miles). He also compounded his error by following the perceived wisdom of the day that stated Eurasia – that is, from the western coast of Europe to the eastern coast of Asia – to be 180 degrees of longitude. Cristóbal went one better by following the estimate for Eurasia at 225 degrees of longitude, an estimate calculated by Greek geographer Marinus of Tyre sometime around 100 CE. This left in Cristóbal’s calculations just 135 degrees of ocean between Portugal, heading due west, and the coasts of Cathay (China). Furthermore, off the coast of China lay Cipangu (Japan), which he believed lay far from its actual position, along with other smaller islands, including the mythical island of Antillia, which was believed to lie some 900 miles southwest of the Azores (which had recently been settled by Portugal in 1432).
Based on these assumptions, the great ocean to the west did not seem so empty after all. The distance from the Canary Islands – Cristóbal’s jumping-off point to Japan – would be 3,700 kilometres with islands in between. It was the trade winds, becoming known as the Easterlies, that filled the sails of his small fleet, driving them across the Atlantic to his first landfall – more on that later.
Map 18. In 1474, Paolo dal Pozzo Toscanelli created a map showing the coastline of Europe and Africa, which he mistakenly believed offered a direct route to China and the Indies.
In 1485, with this potential route in mind, he approached King John II of Portugal and requested the title ‘Great Admiral of the Ocean’, asking to be appointed
