" Indeed, no sultan or Muslim ruler in Islamic history ever kneeled to ask forgiveness before a grand mufti in the way that Henry IV was forced to do before the pope in 1077 in Canossa for challenging papal authority on some key secular matters. Henry VIII of England had to break with Rome entirely simply to secure the divorce he sought from his wife. Thus, intimate linkage between religious and state power marked most of Christian history in a way that has had no parallel in Islam. "

― Graham E. Fuller , A World Without Islam