Pope Benedict XVI has begun the process of beatifying his predecessor John Paul II, the first step to sainthood.
Pilgrims at the Pope's funeral called for his immediate sainthood
"The cause for the beatification of John Paul II is open," the new Roman Catholic leader told priests meeting at Rome's Basilica of St John in Lateran.
The Pope waived the usual rules which require a five-year wait before the Church begins to make someone a saint.
John Paul II died on 2 April, leading to widespread calls from Catholics worldwide for him to be made a saint.
Beatification requires that a miracle has occurred
Group approaches local bishop
After Rome's approval an investigation is launched
Findings are sent to the Congregation for the Causes of Saints
Case is presented to the Pope
Blessed may be accorded a feast day
Relics of the candidate may be venerated
Canonisation (actual sainthood) requires proof of a second miracle
"And now I have a very joyous piece of news for you," Pope Benedict XVI said in Italian before making the announcement in Latin.
The Pope read out a letter from Cardinal Jose Saraiva Martins, the official in charge of sainthood, in which it said that Benedict XVI himself had authorised the start of the beatification process.
The news was met with a standing ovation from the priests attending the meeting.
It comes on the anniversary of an assassination attempt on John Paul II in 1981, when he was shot in St Peter's Square by a Turkish gunman.
Information will now be gathered on the former pope's life and teachings, including all private writings from the period before he became pope, and checked for orthodoxy to ensure that he expressed no heretical views.
Pope John Paul II abandoned the five-year rule when he beatified Mother Teresa
A commission of historians will be appointed to gather all of the documents together, which will then be examined by panels of theologians, and cardinals and bishops.
If a two-thirds majority agree with John Paul II's beatification Pope Benedict XVI will then be called upon to give his own approval.
But Vatican expert Michael Walsh told the BBC that for the process to be complete the Vatican authorities will then have to establish that a miracle has been ascribed to Pope John Paul II.
"They have to prove someone has been miraculously healed... by his intercession, by praying to John Paul II, he or she has recovered from cancer or something of that sort," he said.
In the days following his death Italian media carried a number of reports of alleged miracles attributed to Pope John Paul II, including one claim that an American man suffering from a brain tumour was cured after receiving communion from the late pontiff.
But the alleged miracles occurred during the Pope's lifetime, and the beatification process studies those occurring after the candidate's death.
Beatification allows public veneration of the person and for the person to be known as "Blessed". For actual sainthood, proof of at least two miracles is required.
Beatification allows public veneration of the blessed person
In normal circumstances five years must pass between the death of the person proposed for beatification and the start of the procedure, to avoid emotion playing a part.
However, John Paul II dispensed with this rule himself when in 2003 he beatified Mother Teresa of Calcutta.
The entire process was completed just six years after her death.
On Friday Pope Benedict XVI also announced who would succeed him as head of the Congregation for the Doctrine of the Faith.
Sixty-eight-year-old William Levada, Archbishop of San Francisco, is the first American to hold the post as the Vatican's chief watchdog of orthodoxy.