The Catholic Church is the oldest institution in the western world, and with more than one billion members worldwide, it is the largest Christian church. Its history spans almost 2,000 years and is rooted in the Church's Canon of Scripture and Tradition. At the head of the church is the Pope, who Catholics believe is the successor to Saint Peter whom Christ appointed as the first head of His church. The Pope, according to the religion's doctrine, can speak infallibly on matters of faith and morals. The Catholic Church practises closed communion and only baptised members of the church are permitted to receive the Eucharist, or Holy Communion.
Britain's top Catholic cleric Cardinal Keith O'Brien resigns amid scandal
Top Catholic cleric steps down amid claims of advances towards priest after drinking session
Cardinal Keith O'Brien, Britain's most senior Catholic cleric, resigned with immediate effect in the wake of allegations of inappropriate behaviour.
O'Brien announced in November that he was planning to resign in view of his 75th birthday next month, but he said on Monday: "The Holy Father has now decided that my resignation will take effect today, 25 February."
O'Brien, who is leader of the Catholic Church in Scotland, added: "Looking back over my years of ministry: For any good I have been able to do, I thank God. For any failures, I apologise to all whom I have offended."
The cardinal had denied allegations of inappropriate behaviour by three priests and a former priest that were sent to Rome a week before Pope Benedict's shock resignation announcement on February 11.
O'Brien had been due to be Britain's only cardinal to vote on a replacement for the pope, but he confirmed in his resignation statement that he would not be taking part in the conclave.
"I will not join them for this conclave in person," he said. "I do not wish media attention in Rome to be focused on me - but rather on Pope Benedict XVI and on his successor."
The allegations, dating from the 1980s and reported in The Observer newspaper on Sunday, include claims that one priest received unwanted attention from the cardinal after a late-night drinking session. A spokesman for O'Brien said the allegations were contested.
The four claimants, from the diocese of St Andrews and Edinburgh in Scotland, reported to nuncio Antonio Mennini - the Vatican's ambassador to Britain - that O'Brien had committed "inappropriate acts" going back 33 years, The Observer said.
Aside from the priest who claims he received unwanted attention from the cardinal after a drinking session, another alleges that O'Brien used night prayers as cover for inappropriate contact, according to the paper.
O'Brien has angered the gay community with his conservative stance on homosexuality. He was named "bigot of the year" in 2012 by the rights charity Stonewall.
The Catholic Church has been besieged during Pope Benedict's eight years in office by scandals over paedophilia and other forms of sexual abuse by priests. But the period since he announced his decision to retire on grounds of failing health has been marked by a surge of Italian news media reports, many of them speculative, of gay sex scandals in the Vatican and other allegations of sexual abuse by priests.
The Vatican said yesterday a report into papal documents leaked by Pope Benedict's butler in the so-called Vatileaks scandal last year would remain confidential and only be shown to the next pontiff.
"The Holy Father has decided that the facts of this investigation, the contents of which are known only to himself, will be made available exclusively to the new pontiff," the Vatican said.
Some Italian media had called for the report to be made public ahead of the conclave that will choose the next pope.
The Vatican also said Pope Benedict, who officially resigns on Thursday, has signed a special decree giving cardinals "the possibility to bring forward" a conclave to elect his successor.
"I leave the College of Cardinals the possibility to bring forward the start of the conclave once all cardinals are present, or push the beginning of the election back by a few days should there be serious reasons," the pope said.
The conclave is traditionally held between 15 and 20 days after the papal seat is left vacant.
Additional reporting by The New York Times