From Wikipedia:

Adam Olearius (24 September 1599 – February 22, 1671), born Adam Ölschläger or Oehlschlaeger, was a German scholar, mathematician, geographer and librarian. He became secretary to the ambassador sent by Frederick III, Duke of Holstein-Gottorp, to the Shah of Persia, and published two books about the events and observations during his travels.

He was born at Aschersleben, near Magdeburg. After studying at Leipzig he became librarian and court mathematician to Frederick III, and in 1633 he was appointed secretary to the ambassadors Philip Crusius, jurisconsult, and Otto Bruggemann, a merchant from Hamburg, sent by the duke to Muscovy and Persia in the hope of making arrangements by which his newly-founded city of Friedrichstadt should become the terminus of an overland silk-trade. This embassy started from Gottorp on October 22, 1633, and travelled by Hamburg, Lübeck, Riga, Dorpat (five months' stay), Reval, Narva, Ladoga, and Novgorod to Moscow (August 14, 1634). Here they concluded an advantageous treaty with Tsar Michael of Russia, and returned forthwith to Gottorp (December 14, 1634 – April 7, 1635) to procure the ratification of this arrangement from the duke, before proceeding to Persia.

With this accomplished, they started afresh from Hamburg on 22 October 1635, arrived at Moscow on 29 March 1636; and left Moscow on 30 June for Balakhna near Nizhniy Novgorod, to where they had already sent agents (in 1634/1635) to prepare a vessel for their descent of the Volga. Their voyage down the great river and over the Caspian Sea was slow and hindered by accidents, especially by grounding, as near Darband on 14 November 1636; but at last, by way of Shamakhy (three months' delay here), Ardabil, Soltaniyeh and Kasvin, they reached the Persian court at Isfahan (August 3, 1637), and were received by the Safavid king, Shah Safi (August 16).

Negotiations here were not as successful as at Moscow, and the embassy left Isfahan on 21 December 1637, and returned home by Rasht, Lenkoran, Astrakhan, Kazan, Moscow, and other places. At Reval, Olearius parted from his colleagues (April 15, 1639) and embarked directly for Lübeck. On his way he had made a chart of the Volga, and partly for this reason Michael wished to either persuade or compel him to enter his service. Once back at Gottorp, Olearius became librarian to the duke, who also made him keeper of his cabinet of curiosities, and induced the tsar to excuse his (promised) return to Moscow. Under his care the Gottorp library and cabinet were greatly enriched in manuscripts, books, and oriental and other works of art: in 1651 he purchased, for this purpose