The Queen's trip to Enniskillen in Fermanagh has seen her make a groundbreaking first visit to a Catholic church in either Northern Ireland or the Republic.
She made the short walk across the street from the Anglican Cathedral's deanery, where she privately met seven survivors of the Enniskillen bombing, to St Michael's, filled with local community groups that had gathered to meet her.
The Queen is making her 20th visit to Northern Ireland since first arriving on its shores in 1953, but has never entered a Roman Catholic place of worship, Buckingham Palace confirmed.
Representatives from schools, sports clubs and organisations from both Catholic and Protestant backgrounds stood among impressive flower displays and briefly chatted to the royal couple during their 30-minute stay.
Frank O'Reilly, 63, a driver instructor, born and bred in Enniskillen praised the Queen's visit.
A former choirboy, he has sung for the church for 50 years and performed traditional hymns with colleagues for the royal couple.
He said: "We were told about two weeks ago she was coming and everybody's been excited since then.
"Given the present climate this has been a huge step forward for the Catholic and Nationalist communities."
Canon Peter O'Reilly, from St Michael's, and the Dean of St Macartin's, the Very Rev Kenny Hall, co-operated to deliver the historic cross-community event at their churches which are a stones throw from each other.
Canon O'Reilly said: "My reading of the significance of today is that it is an expression of the unity that there is in this place - a Fermanagh welcome, a gracious Queen, a lovely lady."
The Rt Rev Hall said: "We have worked together to make this a success. And what we are really sending out is a message that we really are one community."
After leaving the Catholic church the Queen went on an impromptu walkabout to meet dozens of the hundreds of residents who had been patiently waiting to catch a glimpse of her.
She wore a Wedgwood blue outfit and hat by Angela Kelly, which featured hand-embroidered white lace on the coat and dress, and was finished off with a shamrock diamond brooch.
She walked past a line of cheering well-wishers and collected flowers.
Dianna Gott, whose four-year-old granddaughter Zara Lindsay presented the Queen with a bunch of flowers, said: "I'll remember this for the rest of my life."
Later the Queen and Duke left in their motorcade for a private lunch at an undisclosed location.
In a thanksgiving service sermon to mark her Diamond Jubilee, the Archbishop of Armagh, the Most Rev Alan Harper, also praised the Queen's groundbreaking visit to the Republic of Ireland last year, which dramatically advanced Anglo-Irish relations.
Her conciliatory words and gestures had allowed many to throw off the "shackles" that had been loosening since 1998's Good Friday Agreement, and to "positively" be themselves, he said.
A congregation of 700 filled the pews of St Macartin's Cathedral in Enniskillen, County Fermanagh, today to hear the Archbishop's sermon to the Queen, Duke of Edinburgh and other distinguished guests including Northern Ireland First Minister Peter Robinson.
The town was the scene of a devastating IRA bomb attack in November 1987 which killed 11 people during a Remembrance Day service, and the Queen will meet relatives of victims later in the day.
The Queen and the Duke of Edinburgh arrived in Northern Ireland earlier for a two-day visit whose start was delayed by almost an hour after bad weather forced the Royal Flight to divert from Enniskillen to Aldergrove Airport, near Belfast.
Tomorrow a historic handshake will take place between the Queen and Sinn Fein's Martin McGuinness in Belfast.
Speaking about the planned meeting, Mr McGuinness, Stormont's Deputy First Minister, has said: "This is about stretching out the hand of peace and reconciliation to Queen Elizabeth who represents hundreds of thousands of unionists in the north."
The Archbishop, head of the church of Ireland, drew parallels between the Queen and her ancestor, Elizabeth I, who addressed Parliament in 1601.
He described how the monarch said in her 17th century speech: "'And though you have had, and may have, many princes more mighty and wise sitting in this seat, yet you never had, nor shall have, any that will be more careful and loving'.
"In that, the first Queen Elizabeth was mistaken. She did not anticipate the reign of her Elizabethan successor for whose 60 years of duty, devotion and service we say 'Thanks be to God'."
The Queen endeared herself to many across Ireland during her state visit to the Republic last year when she laid a wreath at the Garden of Remembrance in Dublin, which honours republicans who died fighting British rule, toured the headquarters of the Gaelic Athletic Association and spoke Irish at a banquet in her honour.
The Archbishop told the congregation today that the tour had great importance: "For many it was an occasion of profound significance and deep emotion. It felt like the completion of an assent, at the highest level, to a process announcing a new day for all the people of this island."
He went on to say: "Shackles, which had been steadily loosening since the ceasefires and the Belfast Agreement, finally fell away, giving us a new freedom to be positively, rather than merely negatively, ourselves."
The Queen is not only the head of the Church of England but has a strong faith, which was highlighted by the Archbishop: "'Everyone then who hears these words of mine and acts on them,' Jesus said, 'will be like the wise man who built his house upon the rock' - the rock of the words and the wisdom of the son of God.
"Your Majesty, it is upon that rock that you have built your life and answered every call of duty."
During the thanksgiving service, the Queen's Diamond Jubilee was commemorated with prayers, including words of support for those who serve their communities.
Cardinal Brady told the congregation: "We pray for all those who work for the public good and whose work builds up community life."
The congregation also said the Diamond Jubilee prayer, composed to mark the Queen's milestone year.
The traditional Irish tune of Danny Boy, also known as Londonderry Air, was performed by pupils from the Portora Royal School 1608 chamber choir.
Before the royal couple left, the national anthem was sung and they then went to a nearby ecclesiastical building for what is believed to be a meeting with families from the Enniskillen bombing.