The sequence of events and maps that led California to be portrayed as an island are much clearer than another famous peninsula-turned-island, Korea. Korea is briefly mentioned in the thirteenth century by Marco Polo as Cauli (Kauli), but otherwise Korea was not described again for European audiences until the late-sixteenth century.
As with Japan and China, most of the earliest bits of information about Korea came from the Jesuits sending letters sent back from East Asia. However, the Jesuits were not actually stationed in Korea; they could only glean impressions from Chinese and Japanese sources. For example, Father Luis Frois wrote of Korea in the context of a war with Japan in 1578. Frois explained that Korea was separated from Japan by a sliver of sea. It had previously been understood to be an island, he explained, but was now known to be a peninsula. However, why Korea was thought to be an island, by who, and how it was found to be a peninsula was not shared with Frois’ curious readers back in Europe.
The first known European to visit Korea was also a Jesuit, Father Gregorio des Cespedes. He accompanied Japanese troops during another war with Korea in 1592. The territory did not agree with Cespedes, who found it bitingly cold. He did not mention anything about the Korean peoples or their geography.
Travel writers, those who actually traveled and those who were more drawn to the armchair voyage, also wrote about Korea. Jan Huygen van Linschoten spent several years in Goa, India, where he had access to Spanish and Portuguese sources. In his Itinerario, first published in German and English in 1598, he suggests Korea is a large island called Core. Richard Hakluyt read the Jesuit letters, which were republished in sets of annual letters. In the second edition of his Principal Navigations (1599), Hakluyt included the information from Frois and Cespedes, scant as it was.
Given the relative dearth of source material, it is not surprising that early maps by Münster, Mercator and Ortelius omitted Korea entirely. The first map to show Korea was Orbis Terrarum Typus de Integro Multis in Locis Emendatus by Petrus Plancius (1594). It included “Corea” as a long, skinny peninsula barely attached to the northeast corner of China. Edward Wright, in the map accompanying Hakluyt’s Principal Navigations, adopted a similar depiction of Korea, as did other mapmakers from the 1590s onward.
Interestingly, the map that accompanied Linschoten’s Itinerario, by Arnold Floris van Langren, shows Korea as a large, round island. However, no other mapmaker is known to have followed this example. Another early island depiction that was widely adopted was that of Luis Teixeira in the 1595 edition of Ortelius’ Theatrum Orbis Terrarum. The long, thin island was used by several cartographers, including Jodocus Hondius, in the seventeenth century. Blaeu also used the Teixeira model before creating a new Korea in later maps that looked like a bat hanging from China, separated from the mainland by the thinnest of waterways.
Confusion over island vs. peninsula continued across seventeenth-century maps. For example, John Speed includes three separate versions of Korea across four maps in his A Prospect of the Most Famous Parts of the World (1626). It is shown on the Teixeira island model, as a thin peninsula, and as a blunt island. These various hypotheses as to the shape of Korea continued to coexist for decades.
Finally, in the 1650s, Father Martino Martini gathered more information and created a new map of Korea. In China from 1642 to 1651, Martini spent a good deal of time with Chinese maps and their makers. Thus, he created new maps showing Korea as a thicker, nearly rectangular peninsula in Bellum Tartaricum (1654) and the Atlas Sinensis (1655).
Also in the 1650s, a Dutch sailor named Hendrick Hamel was shipwrecked on Jeju, an island near southern Korea. Hamel and his fellow survivors would spend thirteen years in Korea, escaping to Nagasaki in 1666. He wrote about the ordeal in a journal that was published in 1668. Although it lacked maps, the ample descriptions confirmed that Korea gave a detailed, first-hand view of Korean geography and culture.
Nevertheless, several maps were published in the early eighteenth-century showing Korea as an island. The island myth, which most likely stemmed from a misreading of Japanese and Chinese maps by early Jesuits, proved to be quite entrenched. Only in 1735 did Jean Baptiste Bourguignon d’Anville produce a map with a roughly accurate outline of the peninsula and a relatively detailed interior.