President Duda: Queen Elizabeth embodied everything that makes Britain truly Great

"My deepest condolences to the Royal Family and all the British people on passing of Her Majesty The Queen. For decades she has been an embodiment of everything that makes Britain truly Great. She will be missed and remembered in Poland and all over the world," President of Poland Andrzej Duda said on Twitter on Thursday.

Poland's Prime Minister Mateusz Morawiecki also sent his condolences.

"We bid farewell to Queen Elizabeth II. She devotedly served her nation throughout her life. And she has served us by her example as a self-sacrificing, wise and prudent leader who knew how to lead her country through any storm," he wrote.

Poland's Foreign Ministry said it had received the news of Queen Elizabeth's passing with great sadness.

"We join in sorrow with members of the Royal Family, the British nation and people around the world. May Your Majesty rest in peace," the Ministry of Foreign Affairs said.

Queen Elizabeth, Britain's longest-reigning monarch, the nation's figurehead and a towering presence on the world stage for seven decades, died peacefully at her home in Scotland on Thursday aged 96.

"The death of my beloved Mother, Her Majesty The Queen, is a moment of the greatest sadness for me and all members of my family," the new king, her eldest son Charles, said.

"We mourn profoundly the passing of a cherished Sovereign and a much-loved mother. I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world," the 73-year-old said in a statement.

News that the queen's health was deteriorating emerged shortly after midday on Thursday when her doctors said she was under medical supervision, prompting her family to rush to Scotland to be by her side.

Thousands gathered outside Buckingham Palace, in central London, and there was a stunned silence when the flag was lowered to half-mast. The crowd surged to the gates as the notice announcing the death of the only monarch most Britons have ever known was attached to the black iron gates.

On the grand Mall boulevard leading to the palace, black London taxis lined up in tribute.

Buckingham Palace said King Charles III and his wife Camilla, the Queen Consort, would remain at Balmoral Castle, where the queen died, before returning to London on Friday, when he is expected to address the nation. 

On Elizabeth's death, Charles automatically becomes monarch of the United Kingdom and the head of state of 14 other realms including Australia, Canada and New Zealand.