Denis Diderot (1713-84) was one of the central figures of the French Enlightenment. During his lifetime he was most known for his role as editor of the Encyclopédie. He enlisted most of the most influential writers and thinkers of the time for this immense project. Diderot was a prolific and enthusiastic writer, writing in a range of genres. He was a novelist, art critic and playwright and the philosophy of materialism and atheism is at the core of his works. Most of these works were published posthumously due to their controversial nature. He received the patronage of Catherine the Great of Russia in late middle age and he undertook his only visit abroad to visit her at the Hermitage at St Petersburg and conversed with the Empress at length.