Dutch cartographer and merchant Isaac Massa’s activity in Muscovy at the beginning of the XVII century was studied. The information about the origin of the map of the northern coast of Russia, the Yamal Peninsula and the Gulf of Ob in the first place was analysed. In Russian historical publications Massa is considered to be a foreign agent who took a hand in the transfer of confidential information on the cartography of Muscovy to the Netherlands. At the same time, the selection of historical facts and documents and the action logic of Massa suggests otherwise. Massa was certainly one of the first who participated in creating the latest maps of the Arctic Ocean coast and the general map of Russia, and he did it with the direct support of influential Russian circles and in the interests of Russia.
We assume that, аt the initial stage of his activity in Russia, Massa represented the interests of the first clan of merchants, the Stroganovs, wishing to include Siberia into the sphere of their direct influence. The material for the preparation of the drawing of Yamal, which was the first image of the peninsula on a map, was probably obtained from the Arkhangelsk coast-dwellers (pomors), who went by sea to trade in their trading station Mangazeya. The assumption that Massa secretly gained access to the so-called Book of the Great Drawing (Kniga Bol’shomu chertezhu) does not stand up to criticism. Massa left Muscovy in the spring of 1609, quite legally taking with him the latest materials on the cartography of Russia and with the task to publish them in the west as soon as possible. Published maps, the actual has consolidated the priority of Russia for the possession of the coast of Western Siberia.
The appearance of Yamal on the map of Russia. Isaac Massa and the searches for north searoute to China