Twelve Keys of Basil Valentine is one of the most important alchemical works available to modern students. First published in 1599 without illustrations, it achieved wider distribution as part of the Tripus Aureus (Golden Tripod) compendium edited by Michael Maier and published at Frankfurt in 1618 by Lucas Jennis. Lucas Jennis provided twelve engraved plates, one for each of the keys. These plates drew upon the allegorical descriptive imagery of the text and added coherence to the symbolism.