Tycho Brahe and the Measure of the Heavens, by John Robert Christianson

What an interesting man. Invented modern astronomy but still never worked out that Copernicus was right. (Tycho favoured a model where everything else orbits the sun, but they all orbit the Earth.) As well as being an observational scientist he was a very laissez faire (hence, best) kind of Christian, even believing in a form of astrology that didn’t impact human free will. And on top of all that, you come to realise what a fascinating powerhouse of ideas Europe was at the time (we were just plodding through the Elizabethan age), with scientists and philosophers sharing ideas freely across national borders … as well as having the plague, religious wars etc.