Muhammad Sven Kalisch converted to Islam at the age of 15 and is a Professor at Münster University, one of Germany's oldest and most respected universities. After working briefly as a lawyer, he began work in 2001 on a postdoctoral thesis in Islamic law in Hamburg, and in 2004 he went on to become Germany's first ever professor of Islamic theology.
In 2008 after extensive research he claimed there was no historical evidence of Muhammad's existence and came to the conclusion that “Muhammad probably never existed”.
In reaction to his conclusions, he was denounced as an apostate, and faced "blistering criticism" from outraged Muslim groups and even some secular German academics. Media in the Muslim world covered the story and police became worried about a violent backlash, telling the professor to move his religious-studies center to more secure premises.
 See Also
- Andrew Higgins - Professor Hired for Outreach to Muslims Delivers a Jolt - Wall Street Journal, November 15, 2008
- Muslim professor who questioned Big Mo’s existence has ditched Islam - The Freethinker, April 21, 2010
- Outspoken German professor of Islam is no longer a Muslim - The Earth Times, April 21, 2010