The comments came as the highest-ranking cleric in the Church of England that the queen heads led prayers at a memorial service for the Duke of Edinburgh.
"The death of Prince Philip fills me with great sorrow," she said in a statement posted by her spokeswoman on Twitter. "His friendship to Germany, his straightforwardness and his sense of duty will not be forgotten," she added.
"We remember the Duke ... above all for his steadfast support for Her Majesty the Queen, not just as her consort, by her side, every day of her reign, but as her husband, has strength and stay of more than 70 years. And it is to Her Majesty, and her family, that our nation's thoughts must turn today."
"The United Kingdom has lost an extraordinary public servant in Prince Philip."
"It was with great sadness that a short time ago I received word from Buckingham Palace that His Royal Highness the Duke of Edinburgh has passed away at the age of 99.
"Prince Philip earned the affection of generations here in the United Kingdom, across the Commonwealth and around the world.
Philip, the Duke of Edinburgh, was admitted to the private King Edward VII's Hospital on Feb. 16 after he felt unwell and was given treatment for an unspecified, but not COVID-19-related, illness.
Since being admitted, the duke has been publicly visited only by his eldest son Prince Charles, the heir to the throne.
"Yes, he's OK, they're keeping an eye on him," William said on a visit to a vaccination centre in eastern England. Royal reporters said he delivered his message with a wink.
A royal source said doctors had been acting out of an abundance of caution and that Philip was in good spirits.