3 September 2010 Last updated at 09:08 ET

Profile: Pope Benedict XVI

Pope Benedict XVI was once dubbed "God's rottweiler" but his pontificate has seen him frequently forced on to the defensive.

Previously known as Cardinal Joseph Ratzinger, the professorial pianist was looking forward to retirement when Pope John Paul II died in 2005. He has said he never wanted to be Pope.

But he took the helm as one of the fiercest storms the Catholic Church has faced in decades - the scandal of child sex abuse by priests - was breaking.

The flood of allegations, lawsuits and official reports into clerical abuse reached a peak in 2009 and 2010.

'Sin within'

The most damaging claims for the Church have been that local dioceses - or even the Vatican itself - were complicit in the cover-up of many of the cases, prevaricating over the punishment of paedophile priests and sometimes moving them to new postings where they continued to abuse.

While some senior Vatican figures initially lashed out at the media or alleged an anti-Catholic conspiracy, the Pope has insisted that the Church accept its own responsibility, pointing directly to "sin within the Church".

He has met and issued an unprecedented apology to victims, promised action and made clear that bishops must report abuse cases to the local authorities.

As Cardinal Ratzinger, he spent 24 years as one of the senior figures in the Vatican, heading the Congregation for the Doctrine of the Faith - once known as the Holy Office of the Inquisition.

It made him John Paul II's "enforcer", and played to his passion for Catholic doctrine.

His high office gave him ultimate oversight of a number of clerical abuse cases.

Critics say he did not grasp the gravity of the crimes involved, allowing them to languish for years without proper attention - or even that he deliberately subordinated the victims' welfare to that of the Church itself.

He has never publicly given his own version of events.

His backers, however, say he has done more than any other pope to confront abuse.

Shortly before his election in 2005, he lamented: "How much filth there is in the Church, and even among those... in the priesthood."

And one of his first acts as Pope was to banish a former Vatican favourite, Father Marcial Maciel, whose sexual and criminal exploits were starting to come to light.

Formative experiences

Joseph Ratzinger was born into a traditional Bavarian farming family in 1927, although his father was a policeman.

The eighth German to become Pope, he speaks many languages and has a fondness for Mozart and Beethoven.

Benedict has carried his love of fine clothes to the Vatican

He was said to have admired the red robes of the visiting archbishop of Munich when he was just five and carried his love of finery to the Vatican, where he has re-introduced papal hats not seen in decades.

At the age of 14, he joined the Hitler Youth, as was required of young Germans of the time.

World War II saw his studies at Traunstein seminary interrupted when he was drafted into an anti-aircraft unit in Munich.

He deserted the German army towards the end of the war and was briefly held as a prisoner-of-war by the Allies in 1945.

The Pope's conservative, traditionalist views were intensified by his experiences during the liberal 1960s.

He taught at the University of Bonn from 1959 and in 1966 took a chair in dogmatic theology at the University of Tuebingen.

However, he was appalled at the prevalence of Marxism among his students.

In his view, religion was being subordinated to a political ideology that he considered "tyrannical, brutal and cruel".

He would later be a leading campaigner against liberation theology, the movement to involve the Church in social activism, which for him was too close to Marxism.

Mild and humble

In 1969 he moved to Regensburg University in his native Bavaria and rose to become its dean and vice-president.

He was named cardinal of Munich by Pope Paul VI in 1977.

At the age of 78, Joseph Ratzinger was the oldest cardinal to become Pope since Clement XII was elected in 1730.

It was always going to be difficult living up to his charismatic predecessor.

As cardinal, Joseph Ratzinger was a prominent figure under John Paul II

"If John Paul II had not been Pope, he would have been a movie star; if Benedict had not been Pope, he would have been a university professor," wrote US Vatican expert John L Allen.

"No surprise that John Paul took the world by storm, while Benedict stands a bit off the beaten path."

Benedict is described by those who know him as laidback, with a mild and humble manner, but with a strong moral core.

One cardinal put it another way, calling him "timid but stubborn".

He has a reputation as a theological conservative, taking uncompromising positions on homosexuality, women priests and contraception.

He espouses Christian compassion - speaking out recently against Roma deportations in France, and against human rights abuses in China and elsewhere.

He criticised the US-led war in Iraq, and has called for more urgency in protecting the environment and fighting the "scandal" of poverty.

PR disasters

A central theme of his papacy has been his defence of fundamental Christian values in the face of what he sees as moral decline across much of Europe.

But he has confounded those who expected him to appoint hard-line traditionalists to key posts, choosing instead many who occupy the Church's centre ground.

However, questions have been raised about those who advise him, after a series of public relations disasters.

Muslims took offence when, in 2006, he quoted a 14th Century Byzantine emperor who said the Prophet Muhammad had brought the world only "evil and inhuman" things.

Then Jews were taken aback when a breakaway group of bishops was welcomed back into the Church fold, including one who was found to be a Holocaust-denier.

Benedict visited Auschwitz in 2006 to pray for the dead of the Holocaust

Thus the Pope's avowed intention of improving inter-faith relations was seriously undermined.

And he even offended fellow Christians, by making it easier for Anglicans to defect to the Catholic Church without discussing the matter with the Church of England beforehand.

At the height of the abuse scandal, senior cardinals also caused outrage by dismissing some allegations as "idle chatter" and asserting a link between homosexuality and paedophilia.

Vatican watchers said the Holy See appeared to have no media strategy to deal with the crisis, and was starting new fires faster than it could put them out.

But although they threaten to undermine the authority of the Church, Benedict seems unlikely to meet such crises by compromising with the liberal modern world.

He has always believed that the strength of the Church comes from an absolute truth that does not bend with the winds.

That approach disappoints those who feel the Church needs to modernise and despair of his intransigence on priestly celibacy or condoms.

But for his supporters, it is exactly why he is the man to lead the Church through such challenging times.