Saint Albert The Great (1200? - 1280)
Albertus Magnus is best known as the teacher of Thomas Aquinas. An advocate of Aristotelian philosophy, he is unique among the medieval scholars in that he alone published commentaries of all known works of Aristotle (including some spurious ones).
His publications and lectures earned him great reknown, and he was quoted as readily as Averroes and Avicenna. He was the only scholar of his time to have earned the title "The Great", which was in use even before he died. The Catholic Church has given him the title of "Universal Doctor."
A contemporary of Roger Bacon, Albert the Great was also one of the earliest natural scientists, and contributed greatly to fields that would eventually become biology, chemistry, physics, astronomy, geography, and mathematics.
Some parts are taken from Britannica.com