The Pope has expressed his condolences to King Charles III upon the death of his mother, the Queen, on Thursday.
The Queen died peacefully at the age of 96 at the Balmoral Estate in Scotland, where she had been spending the summer.
In a telegram to King Charles, the Pope said he was "deeply saddened" to learn of the Queen's death and offered his "heartfelt condolences" to the royal family and the people of the UK and Commonwealth.
In his message, the Pope praised the Queen's "unstinting service" and the Christian faith that sustained her during her long reign.
He assured King Charles of his prayers as he takes up his responsibilities as Britain's new monarch.
"I willingly join all who mourn her loss in praying for the late Queen's eternal rest, and in paying tribute to her life of unstinting service to the good of the Nation and the Commonwealth, her example of devotion to duty, her steadfast witness of faith in Jesus Christ and her firm hope in his promises," the pontiff said.
"Commending her noble soul to the merciful goodness of our Heavenly Father, I assure Your Majesty of my prayers that Almighty God will sustain you with his unfailing grace as you now take up your high responsibilities as King.
"Upon you and all who cherish the memory of your late mother, I invoke an abundance of divine blessings as a pledge of comfort and strength in the Lord," he wrote.
