The Queen is to meet with Pope Francis at a private audience in the Vatican this afternoon during a one day visit to Rome.
It will mark the first time that the two have met, although the Queen - who will celebrate her 88th birthday on April 21 - has spent time with four of Pope Francis' predecessors and last hosted Pope Benedict XVI on his official visit to the UK in 2010.
In addition to being the British monarch and head of the Commonwealth, the Queen also boasts the title 'Defender of the Faith and Supreme Governor of the Church of England'. She has a strong personal Christian faith and tends to give a Gospel-centred message during the annual Christmas speech broadcast by the BBC.
In her address last year, she focused on the limitless nature of God's love and compassion, which is a message that has been central to Pope Francis' missional work so far.
"For Christians, as for all people of faith, reflection, meditation and prayer help us to renew ourselves in God's love, as we strive daily to become better people," she said.
"The Christmas message shows us that this love is for everyone. There is no one beyond its reach."
This was a theme echoed in the Pope's apostolic exhortation Evangelli Gauidum, meaning the Joy of the Gospel, in which he contends: "Time and time again [Christ] bears us on his shoulders. No one can strip us of the dignity bestowed upon us by this boundless and unfailing love. With a tenderness which never disappoints, but is always capable of restoring our joy, he makes it possible for us to lift up our heads and to start anew."
It is not known what the two will discuss, as the meeting will be private, though Britain's ambassador to the Holy See Nigel Baker has said that the visit today will no doubt "help to strengthen the relationship" between the two.
"It is extraordinary how far relations between Britain and the Holy See, and between the Anglican Church and the Catholic Church, have developed since 1952 when she became Queen," he added.
"The visit of her Majesty the Queen to the Vatican and the audience with Pope Francis is a reaffirmation of the strength of the bilateral relationship between the United Kingdom and the Holy See in a year in which we celebrate the centenary of the reestablishment of diplomatic relations with the Holy See.
"We're delighted that the Queen and Pope Francis will have [the] chance to get together."
The visit to Italy is the first foreign trip the Queen has made in over two years. Although she was scheduled to travel to Rome last year, she was forced to cancel due to an illness. She will be accompanied by her husband Prince Phillip today, and the two are also to meet with Italian President Giorgio Napolitano who has issued the pair an official invitation.