  Leonhard Euler was working for the St. Petersburg Academy of Sciences
(Russia) and Prussian Academy of Sciences during various periods of his life.
It is not a popular knowledge about Euler's contacts with Polish scientists of
his era and Poland in general. The aim of this work is to shed some light on
this relationship--mainly with the researchers from the city of Gda\'nsk
(formerly Danzig). As a matter of fact, the famous K\"onigsberg Bridges
Problem, arguably the beginning of the graph theory and topology, originated in
Gda\'nsk.
