In July of 1505, Martin was caught in a horrific thunderstorm. Afraid that he was going to die, he screamed out a vow, “Save me, St. Anna, and I shall become a monk.” St. Anna was the mother of the Virgin Mary and the patron saint of miners.
In 1511, he transferred from the monastery in Erfurt to one in Wittenberg where, after receiving his doctor of theology degree, he became a professor of biblical theology at the newly founded University of Wittenberg.
In 1517, he posted a sheet of theses for discussion on the University’s chapel door. These Ninety-Five Theses set out a devastating critique of the church’s sale of indulgences and explained the fundamentals of justification by grace alone. Luther also sent a copy of the theses to Archbishop Albrecht of Mainz calling on him to end the sale of indulgences. Albrecht was not amused. In Rome, cardinals saw Luther’s theses as an attack on papal authority.