Pope Benedict XVI to step down as leader THE Catholic Church was last night struggling to come to terms with the shock resignation of Pope Benedict XVI, as moves to find a new leader of the world's 1.2 billion Catholics began. The Vatican was thrown into turmoil by the sudden resignation of the 85-year-old Pope yesterday morning. The decision shocked even his closest aides and makes him the first pontiff to quit the post in almost 600 years. His brother said the Pope had been considering quitting for months as his health was deteriorating. In a statement read out in Latin in front of a gathering of cardinals in the Vatican, Pope Benedict said carrying out his duties required "both strength of mind and body." He told them: "After having repeatedly examined my conscience before God, I have come to the certainty that my strengths due to an advanced age are no longer suited to an adequate exercise of the Petrine ministry. I am well aware that this ministry, due to its essential spiritual nature, must be carried out not only by words and deeds but no less with prayer and suffering. However, in today's world, subject to so many rapid changes and shaken by questions of deep relevance for the life of faith, in order to govern the barque of St Peter and proclaim the Gospel, both strength of mind and body are necessary - strength which in the last few months, has deteriorated in me to the extent that I have had to recognise my incapacity to adequately fulfil the ministry entrusted to me. Under Canon Law, the code that governs the Catholic Church, the Pope can resign as long as the resignation is made freely and is published publicly. However, resignations are very rare with the last pope to quit being Gregory XII, who stepped down in 1415. At a press conference at the Vatican yesterday, a spokesman for the Pope, Father Federico Lombardi, said even his closest aides had been unaware of his planned announcement and had been left "incredulous." He said several cardinals, who were not fluent in Latin, did not understand what the Pope had said at the time. But he added the decision showed "great courage" and "determination." Cardinal Keith O'Brien, the leader of Scotland's Catholics, said: "Like many people throughout the world, I was shocked and saddened to hear of the decision by Pope Benedict XVI to resign. I know this decision will have been considered most carefully and that it has come after much prayer and reflection. I will offer my prayers for Pope Benedict and call on the Catholic community of Scotland to join me in praying for him at this time of deterioration in his health as he recognises his incapacity to adequately fulfil the ministry entrusted to him. Cardinal O'Brien will fly to Rome to take part in the conclave, the meeting of cardinals that will elect his successor. He said: "I hope I will also be able to rely on the prayers of Catholics across the world for the Cardinal Electors as we prepare to travel to Rome in order to participate in the conclave, which will be convened to elect a successor as Bishop of Rome and Supreme Pontiff." It has already been suggested the conclave could produce the world's first black pope in modern times, with Cardinal Peter Turkson, from Ghana, and Cardinal Francis Arinze, from Nigeria, being tipped as possible pontiffs. Other leading candidates include Cardinal Marc Ouellet, from Quebec in Canada, and Cardinal Joao Braz de Aviz, from Brazil, who could also bring an end to 1,500 years of European rule in the Vatican. An insight into the current health of the Pope was provided by his brother, Georg Ratzinger, a retired priest. He said Benedict had been advised by his doctor to stop all transatlantic flights, was finding it increasingly difficult to walk and had been considering resigning for months. He added: "His age is weighing on him. At this age, my brother wants more rest. Fr Lombardi said the Pope would move after his resignation into a renovated monastery used by nuns inside the Vatican for "a period of prayer and reflection." It will be unprecedented to have two "Popes" within the Vatican and it is still unclear how Benedict XVI will be addressed after he has retired. Prime Minister David Cameron, who met the Pope during his state visit to Britain, said of him: "He has worked tirelessly to strengthen Britain's relations with the Holy See. His visit to Britain in 2010 is remembered with great respect and affection. He will be missed as a spiritual leader to millions. First Minister Alex Salmond said: "The Scottish Government holds the Holy See in the utmost respect and is aware Pope Benedict's decision will be a great shock to the Catholic community in Scotland and internationally. Like many Scots, I remember with great fondness the resounding success of Pope Benedict's visit to Scotland in 2010 and the Papal Mass celebrated at Bellahouston Park. I wish him a very peaceful retirement. Scottish Labour leader Johann Lamont said: "It is sad to hear that Pope Benedict has been forced to resign due to ill health after such a short time. He touched the hearts of many Scots during his visit to the UK in 2010 and will be remembered fondly by the thousands who saw him that day. Pope Benedict has dedicated his life to the Church and to helping others. His selflessness during his service is matched only by the selflessness of his decision to stand down. Since suffering a stroke in 1991, Benedict has endured a number of health scares. In November 2006, it was reported he had a routine heart examination, while in July 2009, he was hospitalised after he fell and broke his wrist while walking in the Alps. Cardinal Philippe Barbarin, from France, said the Pope had suffered a heart condition for many years and had been taking medication since his initial stroke. News reports in Italy said the Pope found walking even short distances agony due to osteo-arthritis in his knees, hips and ankles, which was why he now used a moving platform to spare him the long walk down the aisle in St Peter's. Benedict had even predicted a short papacy based on his poor health. Last night, a source familiar with the workings of the Vatican said cardinals would already be discussing among themselves who should be the next pope. He said: "Conversations will be taking place, phone calls will be made. It will be very discreet, but the stakes are high. However, there is a saying in Italy that he who enters the conclave as pope emerges as a cardinal: the favourites don't always get the top job. I have convoked you to this Consistory, not only for the three canonisations, but also to communicate to you a decision of great importance for the life of the Church. However, in today's world, subject to so many rapid changes and shaken by questions of deep relevance for the life of faith, in order to govern the barque of St Peter and proclaim the Gospel, both strength of mind and body are necessary, strength which in the last few months has deteriorated in me to the extent that I have had to recognise my incapacity to adequately fulfil the ministry entrusted to me. For this reason, and well aware of the seriousness of this act, with full freedom I declare that I renounce the ministry of Bishop of Rome, Successor of St Peter, entrusted to me by the Cardinals on 19 April, 2005, in such a way, that as from 28 February, 2013, at 20:00 hours, the See of Rome, the See of St Peter, will be vacant and a Conclave to elect the new Supreme Pontiff will have to be convoked by those whose competence it is.