Garci Rodriguez de Montalvo’s 1510 romance novel, Las Sergas de Esplandián (The Adventures of Esplandián), contains the first known mention of the Island of California. He wrote, “Know, that on the right hand of the Indies there is an island called California very close to the side of the Terrestrial Paradise; and it is peopled by black women, without any man among them, for they live in the manner of Amazons.” As a result, early explorers of the New World mistook the Baja Peninsula as an island. In 1533, Fortún Ximénez’s expedition ended in his death at the hands of native inhabitants. Some used this story to further the Montalvo idea of an exotic island, with cities paved with gold, and natives willing to defend their wealth. The idea certainly sold maps.
However, in 1539 Hernán Cortés sent the explorer Francisco de Ulloa and a small crew up the Gulf of California. Ulloa discovered the mouth of the Colorado River, and for about 75 years, maps clearly reflected California as a peninsula. But the island theory was revived during the mid-seventeenth century; one possible factor being Juan de Fuca’s highly disputed claim to finding the legendary Northwest Passage in 1592.
Over a century later, Euseblo Francisco Kino, an Italian Jesuit missionary and scientist, led an expedition to the Baja peninsula to establish his first mission. His maps of the region slowly made their way into the cartographic world; a world sometimes quite separate from that of science. Mapmakers, such as Gerardus Mercator, Abraham Ortelius, and later, Willem Janszoon Blaeu, correctly depicted the Baja peninsula. Yet the majority continued to depict California as an island throughout the seventeenth and eighteenth centuries. The first known instance of the return of this myth was in Michiel Colijn’s 1622 map, published in Amsterdam. This image persisted across the world for well over two centuries, even into the late nineteenth century, when westward expansion was well under way.