Prime Minister Liz Truss has led tributes to the Queen following her death, saying she was “the rock on which modern Britain was built”.
In an address in Downing Street, Ms Truss, who has only been in Number 10 for 48 hours, said: “Britain is the great country it is today because of her.”
She added: “She was the very spirit of Britain, and that spirit will endure.”
Ms Truss said the death of the Queen was “a huge shock to the nation and the world” and “the passing of the second Elizabethan age”.
Queen dies: Latest news and tributes
She continued: “It’s an extraordinary achievement to have presided with such dignity and grace for 70 years. Her life of service stretched beyond most of our living memories.
“In return she was loved and admired by the people in the United Kingdom and all around the world.
“She has been a personal inspiration to me and to many Britons – her devotion to duty is an example to us all.”
The PM ended her speech with “God save the King”.
Labour leader Sir Keir Starmer also marked the passing of “a remarkable sovereign”.
“Above the clashes of politics, she stood not for what the nation fought over, but what it agreed upon. As Britain changed rapidly around her, this dedication became the still point of our turning world,” he said in a statement.
“So as our great Elizabethan era comes to an end, we will honour the late Queen’s memory by keeping alive the values of public service she embodied.
“For seventy years, Queen Elizabeth II stood as the head of our country. But, in spirit, she stood amongst us.”
Liberal Democrat leader Sir Ed Davey said “today, we are a family of nations in mourning”.
He added: “For many of us, including myself, the Queen was an ever fixed mark in our lives. The world changed around us. Politicians came and went. The Queen was our nation’s constant. The Queen represented duty and courage, as well as warmth and compassion.”
Former prime minister Boris Johnson, who gave his final address outside Downing Street just two days ago, described it as “the country’s saddest day”.
“In the hearts of every one of us there is an ache at the passing of our Queen, a deep and personal sense of loss – far more intense, perhaps, than we expected,” he said in a statement.
He continued: “She seemed so timeless and so wonderful that I am afraid we had come to believe, like children, that she would just go on and on.
“Wave after wave of grief is rolling across the world, from Balmoral – where our thoughts are with all the Royal Family – and breaking far beyond this country and throughout that great Commonwealth of nations that she so cherished and which cherished her in return.”
Other former political leaders also paid their respects to the Queen.
Former Conservative PM Sir John Major said she “devoted her life to the service of our nation and its wellbeing”.
“In her public duties she was selfless and wise, with a wonderful generosity of spirit. That is how she lived – and how she led,” Sir John said.
“For millions of people – across the Commonwealth and the wider world – she embodied the heart and soul of our nation, and was admired and respected around the globe.”
He added that the nation “should be grateful that we were blessed with such an example of duty and leadership for so very many years”.
While fellow former Conservative PM Theresa May said the Queen “devoted herself unreservedly to a life of service” and “was respected and admired not only by her own people but far beyond our family of nations”.
“On the 75th anniversary of VE Day, Her Majesty reminded us to ‘never give up, never despair’. It was an address that captured not just the national spirit, but the Elizabethan spirit. A sense of quiet determination, of courage, of faith and of hope in the future.
“It was the honour of my life to serve her as prime minister. But we should never forget that our Queen was a mother, grandmother and great-grandmother.”
Another Conservative former prime minister, David Cameron, added: “No matter how prepared one could be for this day, there are no words that can adequately express the sense of loss our nation will feel.”
He continued: “There simply can be no finer example of dignified public duty and unstinting service and we all owe our sincere gratitude for her continued devotion, living every day by the pledge she made on her 21st birthday.
“Her dedication to our country has been incomparable and, as such, she leaves an enduring legacy.”
The Queen in 96 pictures
Sir Tony Blair said the country has lost “not just our monarch, but the matriarch of our nation”.
The former Labour PM said: “She was not only respected but loved. Respected because of the qualities of duty, decency, integrity and fidelity which she embodied. And loved because of the love and affection she bestowed on us.”
Fellow former Labour prime minister Gordon Brown added: “The United Kingdom, the Commonwealth, and the entire world are joined together in mourning this evening. HM Queen Elizabeth II served this country to the last. I offer my sincere condolences to the Royal Family. May she rest in peace.”
Leaders of the devolved nations also paid their tributes.
Scotland’s First Minister Nicola Sturgeon described it as “a profoundly sad moment for the UK, the Commonwealth and the world”.
She added: “Her life was one of the extraordinary dedication and service. On behalf of the people of Scotland, I convey my deepest condolences to the King and the Royal Family.”
While the First Minister of Wales Mark Drakeford added: “As our longest reigning monarch, she firmly upheld the values and traditions of the British Monarchy. On behalf of the people of Wales, I offer our deepest condolences to Her Majesty’s family during this sad time.”
Democratic Unionist Party leader Sir Jeffrey Donaldson said the Queen had been a “steadfast and unshakeable head of state”. He added: “Her gracious approach has been a constant throughout our lives. Her Majesty led by example in Northern Ireland and reached out the hand of friendship to help with the reconciliation process.”
Sinn Fein vice president Michelle O’Neill said she had learned of the Queen’s death with “deep regret”. She tweeted: “I am grateful for Queen Elizabeth’s significant contribution and determined efforts to advancing peace and reconciliation.”
Paying his respects, Mayor of London Sadiq Khan said: “Throughout a period of unprecedented transformation, she was a source of great stability, inspiring hope during the most testing of times and exemplifying the best of what it means to be British.”