The death certificate confirming the official cause of death of Prince Philip, Queen Elizabeth's husband and prince consort for 73 years, has been made public nearly a month after his passing.

The Duke of Edinburgh was said to have died of "old age" as certified by the head of the royal medical household, Sir Huw Thomas, who has been the royal physician since 2014. According to reports, "old age" is a common cause of death for a patient who is over 80 years old. Philip was 99 years and 10 months old when he died on April 9.

Buckingham Palace did not initially release the cause of death in announcing that the queen's husband passed away. However, Prince Philip was in the hospital for a full month before his death and even underwent heart surgery at St. Bartholomew's.

Sources said that Philip wanted to go home to Windsor to die on his bed, surrounded by his loved ones and the queen. He didn't want to breathe his last at the hospital. His daughter-in-law, the Countess of Wessex, affirmed that the Duke of Edinburgh peacefully passed away on his deathbed.

According to reports, Philip's official death certificate also acknowledged that his job is the "Queen's husband" and that he was formerly known as Philip Mountbatten and Prince Philippos of Greece and Denmark before he became the Duke of Edinburgh.

Meanwhile, Philip's eldest son, Prince Charles, the heir to the queen's throne, personally visited the Welsh guards who were part of the funeral on April 17 to thank them for their service. The Prince of Wales told the guards at Windsor that he's certain his father was "enormously proud" of how they carried out his final wishes.

Philip had been planning his funeral for at least two decades. Royal experts said that the scaled-down ceremony last April, due to the restrictions of the pandemic, was what he would have exactly wished for as a man how preferred not to receive any fuss from the public.

Charles also told the guards that he received plenty of calls about how "marvelous" and "beautiful" the funeral ceremony was executed and it is a credit to the soldiers who made it all happen.

This was Charles' first public appearance since the death of Prince Philip. Previously, the Prince of Wales chose to mourn in the quiet of his home in Wales. However, he did acknowledge and thanked the public for their sympathy and support by posting messages on social media.