Albertus Magnus (1193-1280), German philosopher. Born as the Count von Bollstadt, he became known as Albertus Magnus due to his breadth of knowledge, and was also called the Universal Doctor. Adding much to the knowledge of botany, he was also a keen alchemist, looking at the transmutation of elements. This work led to him producing the first accurate description of arsenic. Magnus wrote commentaries on the work of Aristotle, and documented European scientific knowledge. He became Bishop of Regensburg, retiring to a monastery to complete his studies until his death at Cologne. He was canonised in 1931 by Pius XI.