The Queen's arrival in Northern Ireland has been delayed by bad weather.
Her flight was diverted from Enniskillen, Co Fermanagh, to Belfast International Airport. She later touched down at St Angelo Airport in Enniskillen in a red helicopter with the royal crown on its side.
Crowds in St Macartin's Church of Ireland Cathedral in Enniskillen were told the 11am thanksgiving service was now expected to start at about 11.40am.
A palace spokeswoman said: "Due to inclement weather, the Queen and the Duke of Edinburgh will now fly into Aldergrove Airport (near Belfast) rather than Enniskillen."
She is visiting Northern Ireland for a two-day Diamond Jubilee tour and an historic meeting with Martin McGuinness.
The Queen will shake hands with the Stormont Deputy First Minister - a former IRA commander - on Wednesday in a gesture which will herald another milestone in Anglo-Irish relations.
Ahead of the meeting Mr McGuinness made reference to a famous remark by former prime minister Tony Blair before the 1998 Good Friday peace deal: "There was a lot of talk in the past about someone feeling the hand of history on his shoulder.
"This is about stretching out the hand of peace and reconciliation to Queen Elizabeth who represents hundreds of thousands of unionists in the north.
"It is about me representing my party, wishing to show the unionist people in the north that we are prepared to respect what they believe in, albeit that we are still Irish republicans.
"I am an Irish republican now - after I meet with Queen Elizabeth, I will still be an Irish republican, and just as passionate about freedom, justice and peace, and reconciliation, as I was the day before."