The Prince of Wales, who is next in line to the thrown, turned 72 on Saturday, November 14.
The Duke and Duchess of Cambridge posted a sweet photo of a beaming Prince Charles on social media with the message: "Wishing a very Happy Birthday to His Royal Highness The Prince of Wales!"
The prince has been busy supporting the Queen during Remembrance week – as he does every year – and is expected to mark his personal milestone privately.
Prince Charles and Camilla will spend the special day attending the annual National Day of Mourning in Berlin.
The pair will also take part in the wreath-laying ceremony at the Neue Wache Memorial, before joining the Central Remembrance Ceremony at the German parliament, where the Prince of Wales will deliver a speech.
The eldest child of the Queen and the Duke of Edinburgh, Prince Charles Philip Arthur George was born at Buckingham Palace on November 14, 1948, weighing 7lb 6oz.
He became heir apparent on the death of his grandfather King George VI, when his mother succeeded to the throne on February 6, 1952 when he was just three years old.
He was created Prince of Wales on July 26, 1958 when he was nine years old.
Charles, who is patron of more than 400 organisations, is the oldest heir to the throne for more than 300 years.
Gun salutes would normally be fired in celebration of Charles birthday from Green Park, the Tower of London, and other locations around the country.
But a Ministry of Defence spokeswoman said Covid restrictions meant they would not take place this year.
She said: "We can confirm that, following consultation with key stakeholders, ceremonial gunfire from all saluting stations continues to be temporarily suspended due to national Covid-19 restrictions.
"As such, the Gun Salute due to take place on Saturday 14 November for the birthday of His Royal Highness the Prince of Wales will now not take place.
"Future such events will continue to be regularly reviewed in conjunction with current Government Covid related guidance".