This particular large two sheet chart of the Black Sea was published by the partnership of the two sons of Johannes van Keulen II who flourished sometime between 1757 and 1778. The map appears to be unrecorded in the usual places and draws on the observations of Captain Jan Hendrik Kinsbergen. There are two inset plans of the Bosphorus and Istanbul and another inset of Kerchensky Strait. The whole was prepared by J.van Woensel. This example is from the third part of ‘De Nieuwe Groote Lichtende Zee-Fakkel’ which covered the Mediterranean Sea. The firm of Van Keulen was founded around 1678 by Johannes van Keulen (1654-1715) and in 1680 he published the ‘Zee Atlas’. The multi volume ‘Zee Fakkel’ followed soon after. On his 50th birthday he left the management of the firm to his talented son Gerard (1678-1726). Gerard set about replacing many of his father’s sea charts the first of which was published in 1698. Not in De Vries, Schilder etc., or Koeman.