The German Cardinal is known to be an uncompromising conservative.

Ratzinger is head of the Congregation for the Doctrine of the Faith, the church's chief think tank that has dominated discussions on sexual morality and birth control and prevented liberals from gaining ground.

Ratzinger, 78, is one of the few members of John Paul II's inner circle who are considered 'papabile'.

Photograph: Franco Origlia/Getty Images

Also See: World mourns the Pope's death