British royal family gathers by side of Queen Elizabeth II

"Following further evaluation this morning, The Queen's doctors are concerned for Her Majesty's health and have recommended she remain under medical supervision. The Queen remains comfortable at Balmoral," the Palace said in a statement Thursday, Sputnik reported.

Newly anointed Prime Minister Liz Truss issued a tweet on the royal's health status moments later, saying that "the whole country will be deeply concerned by the news from Buckingham Palace" and emphasizing that her thoughts and those of the nation "are with Her Majesty The Queen and her family at this time."

British media have reported that Prince Charles and Camilla, and Prince William have made or are making their way to Balmoral, her Scottish country residence, to be with the Queen after being informed of her health status.

Queen Elizabeth II, Britain's longest reigning monarch, recently celebrated the platinum jubilee of her rule marking 70 years on the throne. The royal ascended to the throne at the age of 27 in June of 1953, and has been a staple of British political and social life in the decades since. The length of her rule is surpassed only by Louis XIV, who ruled France for 72 years and 110 days during a reign running from 1643-1715.

The Queen postponed a virtual meeting of the Privy Council - a body of senior official advisors on Wednesday after doctors advised her to rest. Elizabeth II appointed Liz Truss as PM and approved her cabinet on Tuesday.

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