The Vatican treasurer, Cardinal George Pell, has vehemently denied any wrongdoing after being charged with sex offences in his native Australia.
He complained that he had been subjected to "relentless character assassination" during a two-year investigation into the "false" claims.
He said the Pope had granted him a leave of absence to fight the charges.
The charges relate to alleged "historical" incidents, police in the state of Victoria said.
The allegations were made by a number of people, said Police Deputy Commissioner Shane Patton.
Cardinal Pell, 76, who is based in the Vatican, is considered the third-ranking official in the Holy See.
He told a news conference at the Holy See that he would travel to Australia if his doctors permitted it.
"I'm looking forward finally to having my day in court," he said.
"I am innocent of these charges, they are false. The whole idea of sexual abuse is abhorrent to me."
The Catholic Church worldwide has in recent years faced a damaging series of allegations relating to sex abuse by priests, and claims that these cases were covered up.
The BBC's James Reynolds says the charges leave the Church - and the Pope - in an uncomfortable position.
After his election in 2013, Pope Francis created a commission to deal with allegations of sexual abuse by clerics. Now he finds that one of his closest advisers faces charges of his own.
In a statement following the announcement of the charges, the Vatican said: "The Holy See expresses its respect for the Australian justice system that will have to decide the merits of the questions raised.
"At the same time, it is important to recall that Cardinal Pell has openly and repeatedly condemned as immoral and intolerable the acts of abuse committed against minors; has co-operated in the past with Australian authorities... has supported the Pontifical Commission for the Protection of Minors; and finally, as a diocesan bishop in Australia, has introduced systems and procedures both for the protection of minors and to provide assistance to victims of abuse."