Among the most important private art collections ever created were those of Imperial Russia. Catherine the Great, guided by Voltaire, amassed treasures on a Herculean scale, laying the basis for what is today the Russian State Hermitage. Favorite courtiers built palaces of unprecedented magnificence in St. Petersburg and Moscow for their vast collections of paintings, antiquities, and decorative arts. In a lively and anecdotal text, Oleg Neverov reassembles...