In 1513 two Camaldolese hermits, Paolo Giustiniani and Pietro Querini, presented the newly elected Pope Leo X a Libellus, or small book, offering a variety of suggestions for what they believed were needed reforms in the Roman Catholic Church. Chief among their recommendations was a crusade against the Ottoman Turks and, ultimately, all of Islam. In A Crusade Against the Turks as a Means of Reforming the Church: Two Camaldolese Hermits’ Advice for Pope Leo X, James G. Kroemer introduces the pope who received the Libellus, and the hermits who wrote and sent it. Kroemer explains why the hermits believed Islam was a danger to Christendom, and what their strategy was to cleanse the world of this perceived threat. The Augustinian Friar Martin Luther is presented as one who also advocated church reform, but questioned using a crusade against Islam as a means of attaining needed changes. This book delves into the desire held by some devout people of faith who wish to achieve what they may consider religious purity at any cost, even by force if necessary.