Deshima is generally described as an artificial fan-shaped island off the coast of Nagasaki, in the southwest of Kyūshū Island. It has an approximate size of two soccer fields, more precisely 214 by 64 meters, 3.969 tsubo, or 13.137 m². It was made to house the Portuguese traders, isolating them in order to prevent Christian missionary activities. Its construction started in 1634 and it was finished in 1636. A consortium of twenty-five major merchants from Nagasaki, the so-called Caserossen, was responsible for building the houses and the storerooms. But when some fifteen to twenty Portuguese were banished after the ‘Christian’ Shimabara uprising of 1637/38, the Nagasaki consortium saw their investment going up in smoke. With the support of the Japanese silk traders, the problems of the Nagasaki consortium were recognized by the local rulers. When the Dutch made the mistake of adding a stone inscribed ‘Anno 1639’ to their newly built warehouse at Hirado, from where they conducted their trade, this ‘Anno,’ undeniably short for ‘Anno Domini’, was immediately recognized as a reference to the Christian religion. The Dutch broke down their warehouse and, to the great relief of the Caserossen, were thus obliged to move their trading post, Factorij, to Deshima.

Small pieces of paper bearing the names of the new owners were pasted onto the map.

From July 1641, the Dutch paid an annual rent of 5,500 tael for Deshima Island, the equivalent of some 8,259 guilders. In the 1680s, this was in between 10 to 12% of //their annual revenue of their trade with Japan. As profits declined during the eighteenth and nineteenth centuries, this percentage increased considerably. Indeed, from the late eighteenth century, one can say that maintaining the trade with Japan was merely a costly matter of prestige. As for the Japanese, the rental income of the island was divided among the members of the Caserossen, based on the size of the façade of their buildings. That is why it is so essential to have this manuscript map of all the buildings on the island, the names of their actual owners, and their exact measurements in ken, one ken being 1.82 meter. It was on the basis of this precious document, rather than simply a map, that the consortium was being paid their share in the annual rent. With a net price of 25,9 tael per ken, even the owner of the smallest building, with a front of just six ken, less than eleven meters, was thus secured of an annual income of 155,4 tael, some 250 guilders.

In Japan, plate 123 in Deshimazu, a compilation of all known materials related to Deshima, both in Japan and abroad, is considered the earliest surviving map of Deshima, commonly dated between 1736 and 1742. However, most likely this is just an early copy after the Leiden map. It was obviously never either used nor updated to record important developments, such as changes of ownership. The Leiden documentary map, however, was for quite some time obviously kept up to date, as is only natural with an original official document. The names of new owners of the houses and storerooms were added on small slips of paper, some of these still in place, but some have gotten loose and are pasted on the sides. The name of the official who was responsible for keeping the document up to date has unfortunately been obliterated.

About the author
Author and art historian M.F.M. (Matthi) Forrer was (the first) Siebold Professor of Material Culture of Pre-modern Japan at Leiden University and curator of the Japanese collection at the Volkenkunde Museum in Leiden. His publications include Kakemono, Five Centuries of Japanese Painting: The Perino Collection (2020), Hokusai: Prints and Drawings (2018), and Nippon: Japan through the Eyes of Philipp Franz von Siebold, 1832-1852 (to be published April 2026).