First a mathematician and then an astronomer, Johannes Kepler (1571-1630) overcame tremendous odds: lifelong illness, personal disasters, religious and political oppression, and financial difficulties, to become the founder of theoretical astronomy. In this thoroughly researched biography we are immersed in the difficult life and times of the Counter-Reformation. With painstaking care the author describes Kepler's poor childhood, his clerical training, teaching jobs, his arrival in the world of the great as imperial mathematician to Rudolf II at Prague, his methods of deduction and calculation resulting in his theories concerning the speed of planets, and the shape of their orbits. His new laws exploded the accepted explanation of the universe, but not without considerable opposition from the scientists of his day and the Catholic Church. Heavily weighted with technical detail this book has great value but only for the young adult with a mania for mathematics and/or astronomy, their history and evolution.