The 13th-century friar Roger Bacon has a good claim to be known as the West's first true scientist. Born in 1219, he was passionately interested in the natural world and how things worked. In this age of religious intolerance and superstition he was banned from writing on such dangerous topics by his Order, and it was only when a new Pope proved sympathetic that he began his encyclopedia of knowledge, on everything from optics to alchemy. Sadly the enlightened Pope died before he could read it; and Bacon was tried as a magician and incarcerated for 10 years. After his death, legend transformed Bacon into a mythical sorcerer Doctor Mirabilis, but we recognize that his books were the first flowering of the scientific knowledge that would transform our world. This work is both a biography and a picture of the times - an intellectual map of the medieval world in which advances were made and controversies flourished.