The Dutchman Joris Carolus was the first to distinctly mark a group of small islands south of Edgeøya. The Muscovy Company's map (1625) showed a vague mass of islands as well, some labeled, such as Wester I., Beare Iland, Heling I., and the Hopeless Iles. (perhaps Kong Ludvigøyane). G. Valk and P. Schenk (c. 1662) were the first to place a "great vague mass of islands stretching round the coast" south of Edgeøya. William Scoresby (1820) is thought to have been the first to label them with the popular name of Thousand Islands, the name they retain to this day.
Purchas, S. 1625. Hakluytus Posthumus or Purchas His Pilgrimes: Contayning a History of the World in Sea Voyages and Lande Travells by Englishmen and others. Volumes XIII and XIV (Reprint 1906 J. Maclehose and sons).