Heinricus Institoris is the major author of the Malleus Maleficarum, the best known early-modern textbook on witchcraft. This work was heavily influenced by Institoris's activities as inquisitor in Ravensburg in 1484 and Innsbruck in 1485. This volume contains the only complete translations of a large number of documents pertaining to these inquisitions, and is a companion to a new (and the only complete) edition of these texts, which shed much light on the composition of the Malleus Maleficarum in general.