The cardinals of the Roman Catholic Church have elected as Pope perhaps the most controversial, divisive and reactionary of all the plausible candidates. Cardinal Joseph Ratzinger becomes Pope Benedict XVI, at 78 the oldest pope elected in the past 100 years after the swiftest conclave of modern times. It lasted just over 24 hours.
As head of the Church's Congregation for the Doctrine of the Faith, he has been not only the Vatican's guardian of orthodoxy since 1981, but in recent years he has been, in effect, second-in-command to Pope John Paul II. In that role he has been associated with all of John Paul's most hardline policies.
Cardinal Ratzinger was born in Bavaria in 1927, a policeman's son. As a child he was a member of the Hitler Youth, though he was never a member of the Nazi Party. His studies for the priesthood were interrupted in the war when he was drafted into an anti-aircraft unit but eventually he deserted. He ended the war as a prisoner of the Americans.
From the outset he was marked out as an intellectual of extraordinary capacity, and he was a radical in his youth. One of his doctoral dissertations was rejected when his superiors accused him - ironically given the subject of his final sermon just before the conclave - of relativism. After a circuit of famous German theological faculties, in Bonn, Münster, Tübingen and Regensburg, he became a theological adviser at the Second Vatican Council - the Church's great reforming movement in the 1960s. There he penned a famous line about the Holy Office, the body previously known as the Inquisition, asserting that its "methods and behaviour do not conform to the modern era and are a source of scandal to the world".
At that time, no one would have suspected that Joseph Ratzinger, the energetic apostle of a reformed vision of the church, would go on to head that same office - and have exactly the same accusations levelled against him.
For the softly spoken, courteous, Bavarian cardinal is the iron fist in Catholicism's velvet glove. Nicknamed "God's rottweiler" and the "Panzerkardinal" he takes the same unyielding stance on issues such as artificial contraception, abortion and homosexuality - which he has personally called "intrinsically evil". He called for pro-abortion politicians to be denied communion during the US election campaign. He has argued that Europe should be re-Christianised and that Turkey should not be admitted into the European Union.
In many areas he is more hardline than his predecessor. He undermined Pope John Paul II's attempts at reconciliation with the Orthodox churches. After the last pope visited Athens to apologies for the Great Schism of the 11th century, Cardinal Ratzinger issued a document insisting that the Catholic Church was the "mother" of other Christian denominations as opposed to a "sister," the more common description in ecumenical circles. It was typical of his stance as a more rigid outrider to the positions adopted by John Paul II.
What is said to have changed the future pope from a leading progressive to the architect of reactionary restoration today was horror at the German student revolutions of 1968. Since that point he has steadily retreated into an increasingly conservative stance.
By 1997 he had rowed back to the point where he said that the way Pope Paul VI dumped the Latin Mass and imposed a vernacular version had created a "tragic breach" in the tradition. "I am convinced that the crisis in the Church that we are experiencing today is, to a large extent, due to the disintegration of the liturgy," he wrote. He has since said he hoped for a new generation of bishops who would restore Latin to the liturgy and curb the "wild excesses" of the years since Vatican II.
In 1977 he was made Archbishop of Munich and became a cardinal a few months later. Soon after Pope John Paul II made him the Vatican's guardian of orthodoxy. From the outset, Cardinal Ratzinger moved to stamp out liberation theology, a trend in Catholic thought mainly in Latin America which mixed Catholic theology with Marxist analysis of capitalism. Where John Paul II, with his Polish background, had some sympathty with the movement and its critique of the cruelties of capitalism, the German theologian had none. He decided to stamp it out.
Throughout the 1980s Cardinal Ratzinger began investigating liberation theology, having decided that it wanted redemption inside history which he saw as a heresy. His critics say he misunderstood the notion and saw these Third World movements through too European a lens. In May 1985, Ratzinger notified its leading exponent, the Franciscan Father Leonardo Boff, that he was to be silenced. The crackdown had begun.
As Prefect of the Congregation for the Doctrine of the Faith, Cardinal Ratzinger became notorious for his readiness to boot liberal theologians out of their university posts and, if necessary, right out of the church. Right wingers in the Church say that his stance has been the intellectual salvation of Roman Catholicism in a time of confusion and compromise. But others see in the future Pope's hammering of dissent an attempt to restore a model of church - clerical, dogmatic and rule-bound - which Vatican II sought to overthrow.
It all brought back echoes not heard in the church since the clampdown on modernism at the end of the 19th century and the heresy trails of the Reformation. Infallibility was expanded, to include the ban on women's ordination and the invalidity of ordinations in the Anglican church.
Almost all the Catholic controversy in the past 20 years somehow involved Joseph Ratzinger. In all this the new Pope demonstrated all the authoritarianism of John Paul and none of his warmth or spontaneity.
Towards the end of Pope John Paul II's life, the man who was to be his successor took on more and more tasks. The late pope allowed "his trusted friend" to make his office the most powerful in the Vatican, exercising an informal veto over the key job of appointing bishops. His hardline influence extended even to the ruling that parishes should not use female altar servers and choristers. In all of this the new Pope exhibited the stern unbending face of Catholicism.
After the death of Pope John Paul II, Cardinal Ratzinger, as Dean of the College of Cardinals, took charge of the formal morning meetings of cardinals during the nine days of mourning. As one of only two cardinals who was not appointed by John Paul - his red hat having been awarded by Pope Paul VI - he had a knowledge of the running of a conclave which was not shared by the rest.
His authority was enhanced when he preached an emotional sermon at John Paul's funeral, which concentrated on the late pope's positive qualities, while avoiding any mention of matters that would have embarrassed guests like President Bush such as John Paul II's opposition to thewar in Iraq.
Then, just before the conclave, he preached a sermon which was effectively a manifesto for his papacy. In St Peter's he attacked modern relativism with its anything-goes philosophies. "We are moving towards a dictatorship of relativism which does not recognise anything as definitive and has as its highest value one's own ego and one's own desires ... from Marxism to free-market liberalism to even libertarianism, from collectivism to radical individualism, from atheism to a vague religion, from agnosticism to syncretism and so forth."
It seems to have been a clinching moment. Liberal cardinals were wrong-footed and unable to find a candidate to stop him.
On the balcony of St Peter's he chose the name Benedict. The last Pope Benedict was known as a man of peace, who sought to prevent and then end the First World War. But it will take more than a gesture to convince many of his critics that a Ratzinger papacy will be anything other than a time of war within the church.
How the world reacted
DR ROWAN WILLIAMS, ARCHBISHOP OF CANTERBURY
"He is a theologian of great stature, who has written some profound reflections on the nature of God and the Church. His choice of the name Benedict suggests he wants to connect his vision of the Church to the monastic spirit of service and contemplation."
CHIEF RABBI DR JONATHAN SACKS
"As a global leader in a global age, his voice will be important in framing some of the great challenges of the 21st century. I hope therefore that he will speak in defence of the covenant of human solidarity in alleviating poverty and disease, illiteracy and absence of hope."
GERHARD SCHRÖDER, GERMAN CHANCELLOR
"This is a great honour for Germany. I think he will be a worthy successor to Pope John Paul II. I congratulate him on behalf of the government and all Germans.
KOFI ANNAN, THE SECRETARY GENERAL OF THE UN
"His Holiness brings a wealth of experience to this exalted office. The UN and the Holy See share a strong commitment to peace, social justice, human dignity, religious freedom and mutual respect among the world's religions."
JACQUES CHIRAC, FRENCH PRESIDENT
"I send Pope Benedict XVI my warmest congratulations and sincere good wishes for the high mission that has just been entrusted on the head of the Catholic Church."
MARY McALEESE, IRISH PRESIDENT
"May your acceptance of this tremendous burden of service bear fruit in our world. May God give you strength for these new cares."
BILL FRIST, US SENATE MAJORITY LEADER
"I'm confident Pope Benedict XVI is blessed with the same compassion and vision that made Pope John Paul II one of the world's most revered and respected voices."