Complex sentence: Paris in the 18th century was the second-largest city in Europe, after London, and was the main stage of the Enlightenment and the French Revolution, and the home of Voltaire and Robespierre.
Split into simpler sentences: Paris in the 18th century was the second-largest city in Europe, after London. It was the main stage of the Enlightenment and the French Revolution, and the home of Voltaire and Robespierre.