VATICAN CITY- The Vatican on Tuesday prepared for a momentous transition after Pope Benedict XVI announced he will resign on February 28, insisting that a recent heart operation had no bearing on his decision.The rumour mill over a successor went into overtime after what will be only the second voluntary papal resignation in Catholicism’s 2,000-year history, although no clear favourite has emerged. The 85-year-old Benedict made the surprise announcement on Monday that he will step down after just short of eight years, saying he could no longer fulfil his duties in a fast-changing world. The Vatican on Tuesday stressed Benedict will have no role in choosing his successor and will retire to a life of quiet contemplation and academic research in a little-known monastery inside the Vatican walls. The retirement will create an unprecedented “cohabitation” - a pope and his predecessor within a stone’s throw of each other in the tiny city state.So unusual is the situation that the Vatican must decide on a title for the pope once he resigns, with spokesman Federico Lombardi saying he could not simply revert to being Cardinal Joseph Ratzinger. He is likely to receive an honorific title like “Bishop of Emeritus of Rome”, Lombardi said. The spokesman also revealed that the pope had an operation to replace the batteries in his pacemaker three months ago but said the surgery, which was kept quiet, had no bearing on his decision.The Holy See has emphasised that Benedict’s decision was not due to any specific illness or event and was part of a long thought process. Lombardi said the pope’s Ash Wednesday mass, which kicks off a period of penitence before Easter in the Christian calendar, would be his last mass in public before his resignation and would exceptionally be held in St Peter’s Basilica instead of a smaller Rome church as tradition dictates. At a meeting with Rome parish priests on Thursday, the outgoing pope is also expected to speak about his personal experiences during the Second Vatican Council in the 1960s which introduced sweeping reforms to modernise the face of the Roman Catholic Church. Then on February 27 there will be a general audience held in St Peter’s Square, where crowds are expected to bid farewell to the pope. The weekly audience is normally a more discreet affair inside the Vatican. No date has been set for a conclave to elect his successor and Secretary of State Tarcisio Bertone will govern the Church during the transition.The Vatican has said it expects a new pope to be in place in time for Easter, which falls on March 31 this year, although the decision is ultimately up to the world’s 117 elector cardinals meeting in a secret conclave. Only a handful advisors knew of the pope’s plan and many in the Vatican hierarchy were caught off guard, with Cardinal Angelo Sodano saying it was “like a lightning bolt in a clear blue sky.”Within hours of the announcement, an actual lightning bolt struck the tip of the dome of St Peter’s Basilica, an eerie image captured by an AFP photographer. Several observers said Benedict wanted to avoid the fate of his predecessor and mentor, John Paul II, who turned his long and debilitating illness into a living example of Christ’s suffering.Ordinary faithful among the world’s 1.2 billion Catholics were stunned by the decision, particularly as the pope is the first to resign of his own free will in over 700 years.Some said the move was a courageous act that would breathe new life into a Church struggling with multiple crises and could possibly set a precedent for ageing popes.“This signals the end of the tradition of popes for life. It is an example and a suggestion for future popes,” said Marco Politi, a biographer of Benedict and columnist for Il Fatto Quotidiano.Others expressed dismay that a leader whose election by the Church’s cardinals is believed to be divinely inspired could simply decide to quit.Many ordinary Catholics looked forward to a more progressive pope after the deep conservatism of Benedict and his long-serving predecessor John Paul II.“I think the new pope will have to be an innovator on many of the problems of the modern world,” said Mimmo, a pensioner in Rome.“I think the Church should be more open on the idea of priestly celibacy and on the ordination of women priests,” he said.The pope’s eight-year rule - among the shortest in the Church’s modern history - also earned him plenty of enemies, however, from the gay community and AIDS activists to the many shocked by the abuses of paedophile priests and multiple cover-ups.An academic theologian and the author of numerous tomes, including a trilogy on the life of Jesus Christ, the pope was often seen as detached from the day-to-day running of the Church.Still he tried hard to reach out to a younger, global audience - including by opening a Twitter account just before Christmas with the handle “Pontifex” (“Pontiff” in Latin).Only one other pope has resigned because of an inability to carry on - Celestine V in 1294 - a humble hermit who stepped down after just a few months saying he could no longer bear the intrigue of Rome.Speculation over who could be the next pope is rife, although seasoned observers cautioned that predictions of future popes are notoriously unreliable.The field appears wide open, with some saying the papacy could return to an Italian for the first time since 1978, others saying it could go to a North American candidate and still others saying Africa or Asia could yield the next pope.