Short answers, pulled from the story.
René Descartes published his Discourse on the Method in 1637. This publication marked a turning point that introduced a radical approach to knowledge requiring doubt unless there was a well-founded reason for acceptance.
Denis Diderot compiled the Encyclopedia between 1751 and 1772 in thirty-five volumes alongside Jean le Rond d'Alembert and a team of one hundred fifty others. This massive publication helped spread Enlightenment ideas across Europe and beyond.
The French Revolution began in 1789 when France dismantled its Ancien régime rigid social hierarchy. Alexis de Tocqueville proposed this revolution as an inevitable result of radical opposition created between monarchy and men of letters.
Frederick the Great ruled Prussia from 1740 to 1786 and invited Voltaire to live at his palace after imprisoning him under previous French government. He explained his principal occupation was combating ignorance prejudice while enlightening minds and cultivating morality within means available.
The Haitian Revolution began in 1791 and ended in 1804 showing how Enlightenment ideas formed complex transcultural flows. The French National Convention abolished slavery in 1794 forced by events unfolding in Saint-Domingue colony.