As an Augustinian monk in Germany, I also was an early supporter of Martin Luther.
Because I did not conform with the Catholic faith and was unhappy with taking money from the poor, I was forced out of the monastery, sought refuge with Lutherans, and became a professor of mathematics at Jena University.
My most important published work is Arithmetica Integra, where I introduced innovations in mathematical notation, such as +, , √ or even representing multiplication by juxtaposition (i.e. no intervening symbol).
I also introduced the term "exponent" amidst tables of integers and powers of 2; mathematicians today claim my work is an early version of a logarithmic table.
My big mistake was publishing anonymously Ein Rechenbuchlin vom EndChrist. Apocalyps in Apocalypsim (A Book of Arithmetic about the AntiChrist. A Revelation in the Revelation), where I predicted that Judgement Day and the world's end was at 8am on October 19, 1533...when this prediction failed, I never made another prediction.
Answer:
Michael Stifel (1487  1567)
