The Queen has attended an Easter service at Windsor Castle on the day she celebrates her 93rd birthday.
She was presented with flowers and a crowd sang "Happy Birthday" as she left St George's Chapel.
In an Easter message, Prime Minister Theresa May said the UK "must stand up for the right of everyone" to practise their faith in peace.
And Labour leader Jeremy Corbyn compared the experience of Jesus to the challenges facing some refugees today.
The Queen was joined for the Easter Sunday service by family members including the Duke and Duchess of Cambridge and the Duke of Sussex.
The Duke of Edinburgh, who has retired from public duties, and the Duchess of Sussex, who is heavily pregnant, did not attend.
But Prince Harry and Meghan posted a joint birthday greeting to the Queen on Instagram, saying: "Happy Birthday Your Majesty, Ma'am, Granny."
As the Queen left the chapel, she was presented with two posies - one yellow and one white - by two boys.
Gun salutes will also be fired in London to mark her birthday - although she will have to wait a day, as they are never done on a Sunday.
The Queen celebrates two birthdays each year - 21 April is her actual birthday and she also has an official one on the second Saturday in June, which is commemorated with the Trooping the Colour parade.
The Archbishop of Canterbury, Justin Welby, used his Easter message to say the resurrection of Jesus showed "injustice and oppression don't have the last word".
"The risen Jesus is the one who makes our broken lives whole," he said.
In her Easter message, the prime minister said she will spend her time "giving thanks in church", but for many Christians "such simple acts of faith can bring huge danger".
About 245 million Christians worldwide are estimated to be facing persecution.
Mrs May, a vicar's daughter and practising Christian, said: "Churches have been attacked. Christians murdered. Families forced to flee their homes.
"That is why the government has launched a global review into the persecution of Christians.
"We must stand up for the right of everyone, no matter what their religion, to practise their faith in peace."
The government review, led by the Bishop of Truro, was launched in December to look into how much help the UK gives persecuted Christians.
In the Labour leader's Easter message, Mr Corbyn said the experiences of Jesus as a refugee were "still familiar to us today".
He said Jesus was "a refugee whose parents were forced to flee their home", who went on to "know what it was to be ostracised, rejected and tortured".
He added: "The refugee crisis is a moral test. Jesus taught us to respect refugees."
Mr Corbyn also used his message to criticise the government for failing to take in child refugees, as well as Home Secretary Sajid Javid's handling of the Channel migrant crossings over the winter.
He said: "In Britain, we have a proud history of providing a safe refuge to those in need. But this government refuses to meet our legal obligations to child refugees in Europe as required by the Dubs Amendment."
The Dubs amendment, designed by the Labour peer and former child refugee Lord Dubs, was a scheme which aimed to let unaccompanied migrant children into the UK - but it was not extended by the government in 2017.
The Home Office responded by saying that the UK had provided protection to over 34,500 children since the start of 2010 and the government was "determined to deliver on its commitment" to relocating 480 children under the "Dubs amendment".