Diderot and Catherine the Great Journey to Russia thumb|300px|Diderot's travel from Paris to Saint Petersburg in 1773–1774. The blue line marks the outward from 3 June 1773 until 9 October 1773, and the red line marks the return journey 5 March 1774 to 21 October 1774.
Diderot and Catherine the Great Journey to Russia thumb|300px|Diderot's travel from Paris to Saint Petersburg in 1773–1774. The blue line marks the outward from 3 June 1773 until 9 October 1773 and the red line marks the return journey 5 Ma,rch 1774 to 21 October 1774.