This astonishing audacity and almost provocative text enjoyed extraordinary success throughout the 18th century. It was published throughout Europe, it was copied by hand dozens of times, Queen Christina of Sweden offered a small fortune to obtain a copy and there was endless discussion about the probable author. It was even attributed to Frederick II of Prussia. The Parisian police, alerted, ended up arresting the booksellers who sold it. The reason was simple: it is that, according to the mysterious author, visibly familiar with Spinoza's work, all religions were fables maintained by impostors, in cahoots with political power to tyrannize the people. In reality, it dated from the end of the 17th century and was probably inspired by Spinoza's archives, kept in the Netherlands after the philosopher's death. Unknown to the general public, even kept under wraps for obvious reasons, it demonstrates that a century before the Europe of the Enlightenment existed a powerful libertarian current, the very one that led to the French Revolution. The historical importance of the Treaty of the Three Imposters cannot hide its modernity and topicality in this 21st century, which is already darkening with religious conflicts.