The Archbishop of Canterbury yesterday received one of the top honours awarded by the Catholic Church.
Former Archbishop of Wales Dr Rowan Williams is the first Archbishop of Canterbury to be made Knight Grand Cross - the highest grade - of the Royal Order of Francis I.
The award is for developing and encouraging dialogue between Protestants and Catholics both in his time as Archbishop of Canterbury and in his previous positions, the ceremony's organisers said.
Dr Williams visited Rome last month and met the Pope for the first time in what was seen as an important step towards further improving relations between Catholics and Anglicans.
Lady Thatcher and Northern Ireland secretary Paul Murphy, MP for Torfaen, were also among those given the top religious honours at a ceremony in Westminster Cathedral.
Others were recognised for contributing to the life of the Catholic Church and supporting charities and humanitarian initiatives including London's Passage homeless centre.
The ancient award of Knight of the Sacred Military Constantinian Order of St George was given to Mr Murphy for his work promoting peace in Northern Ireland.
Former Chief of Defence Staff General Lord Guthrie received the Knighthood of the Sacred Military Constantinian Order of St George.
Lady Thatcher was made Dame Grand Cross - the highest honour - of the Royal Order of Francis I for lifetime work towards inter-faith dialogue.
The ceremony was presided over by eminent figures including Cardinal Mario Francesco Pompedda, one of the most senior Vatican cardinals and the most senior cardinal to visit Britain since the Pope in 1982.
Also presiding was Cardinal Cormac Murphy-O'Connor, Archbishop of Westminster.
Among those who sent messages of support were the Queen and Prime Minister Tony Blair.