Ratzinger was one of Pope John Paul's closest advisors, and carried out many of the pontiff's duties during his last days.

He also delivered the homily at the funeral service for the Pope.

Ratzinger is the dean of the College of Cardinals, and is the head of the Congregation for the Doctrine of the Faith.

His views are considered extremely conservative, and he has been known to punish liberal thinkers in the church.

Ratzinger has alienated other Christian denominations by saying they are not real churches.

He also condemned homosexuality and same-sex marriage in 1986, and denounced "radical feminism" in 2004.

In the days leading up to the conclave, Ratzinger published a book in Germany, arguing that Europe must reclaim its Christian heritage.

Ratzinger has attracted a following, who have a fan club website, www.ratzingerfanclub.com.