"To explore the possibilities of both commerce and conquest Peter dispatched to Iran a young, bright official, Artemii Volynskii, who was given written instructions to note, when passing through the possessions of the Shah, everything about harbours, towns and settlements, and especially about rivers that flow into the Caspian; then in Peter's own hand was added, "and how far along such rivers can one sail from the sea, and whether there is a river that flows into that sea from India"."
Avery, Peter, Gavin Hambly, and C. P. Melville. The Cambridge History of Iran. Vol. 7 (Cambridge: Cambridge University Press, 2008), 315.