Thousands of Australians have gathered in the Vatican to celebrate the canonisation of the country's first saint.
Mother Mary MacKillop was canonised by Pope Benedict at a solemn ceremony in Saint Peter's Square alongside five other new saints.
Tens of thousands of Australian pilgrims were said to have travelled to Rome to attend the mass, where the pope read a sainthood decree for MacKillop, one of the few saints in Church history who were excommunicated and later rehabilitated.
The nun was a 19th-century "whistleblower" who activists say should be the patron of victims of sexual abuse by priests because she was punished for exposing it.
Documents recently uncovered in Australia showed that MacKillop was temporarily banished from the Church in part because her order uncovered a case of sexual abuse of a boy by an Irish priest.
Pope Benedict spoke of her "saintly example of zeal, perseverance and prayer" and the many challenges she faced.
Australian Mark Fabbro, who said he had been sexually abused by a priest at the age of 11, said: "Well for me as a survivor of sex abuse by a priest this is a very important day for me. Mary MacKillop was a carer of the disadvantaged ... a particular priest who was brought to light by her for abusing children so she was protecting children of child abuse."
The Catholic Church has been rocked by scandal involving the sexual abuse of children by priests over a period of decades. The Pope met with victims of sexual abuse on most of his recent foreign trips, including in Australia in 2008.