As well as being an important medieval theologian, Albertus Magnus (Albert the Great) also made significant contributions to the study of astronomy, geography and natural philosophy, and his studies of the natural world led Pope Pius XII to declare Albertus the patron saint of the natural sciences. Dante Alighieri acknowledged a substantial debt to Albertus's work, and in the Divine Comedy placed him equal with his celebrated student and brother Dominican Thomas Aquinas. In this, the first full, scholarly biography in English for nearly a century, Irven M. Resnick and Kenneth F. Kitchell Jr narrate Albertus's key contributions to natural philosophy and the history of science, while also revealing the insights into medieval life and customs that his writings provide.