The Duke of Edinburgh spent his sixth night in hospital after being admitted on Feb. 16 as a “precautionary measure” for undisclosed heath reasons and, according to several news outlets, is expected to remain in a doctor’s care for “observation and rest” for much of this week. The 99-year-old “Iron Duke” was visited by his son Prince Charles, who made the 200-mile round-trip drive from his country home in Highgrove to King Edward VII’s Hospital in London on Feb. 20. Cameras caught the teary-eyed prince looking upset after his 30-minute visit. Royal commentator Russell Myers revealed to ITV’s Lorraine that Harry is currently self-isolating at his home in California with Duchess Meghan and baby Archie. “If he does have to jump on a jet to get back here if the worse was to happen to Prince Philip, then he wants to be able to do that at a moment’s notice,” said Myers. On Feb. 22, veteran royal photographer Arthur Edwards asked Prince William about his grandfather’s condition during an official visit to King’s Lynn Corn Exchange in Norfolk. “He is okay–they’re keeping an eye on him,” the Duke of Cambridge replied. There has been no additional update from Buckingham Palace since Philip was admitted to the hospital, other than to say the prince remains “in good spirits.” “Harry has to be thinking about the close relationship he has always shared with Philip right now,” said a royal source. “Regardless of how strained relations have become between him and the royals, he will need to be with the family should the worst happen. There is no doubt that would shake him out of this California-mindset of leaving royal life behind and bring him back into the fold—at least temporarily.” To find out more about Prince Harry’s unique bond with Prince Philip, read on. And for another sweet story about Philip, check out The Secret Nickname Prince Philip Has for Queen Elizabeth. In 1997, as the planning of Princess Diana’s funeral grew more contentious between the royals and the princess’s brother, Earl Charles Spencer, Philip emerged as the peacemaker. While Diana’s brother did not believe William and Harry should walk behind Diana’s coffin, Prince Charles was insistent. Then 15-year-old William was adamant that he would not walk in the processional, while 12-year-old Harry was too confused and upset by his mother’s death to be able to decide something so critically important. It was Philip (who had not planned to walk) who gently asked both boys, “If I walk, will you walk with me?” And so, with their grandfather there for much needed support, William and Harry made that heartbreaking journey through the streets of London to Westminster Abbey on Sept. 6, 1997. And for more on Diana’s tragic passing, check out The 6 Biggest Unanswered Questions Surrounding Princess Diana’s Death. Philip has always had a huge influence in Harry’s life. Their shared connection grew even stronger when Harry chose to enter the military. “Philip could see how Harry had found his place in the army,” a royal insider told Best Life. “He was impressed with Harry’s dedication and commitment to serving his country.“ae0fcc31ae342fd3a1346ebb1f342fcb When Philip retired, Harry took over one of his grandfather’s most important roles as Captain General Royal Marines, which he recently lost when Queen Elizabeth took back all of Harry’s military titles. And for more on the drama behind that decision, check out Why the Queen Won’t Give Prince Harry Back His Military Titles. The original royal “outsider,” who had given up his claim to the Greek throne to become a British citizen in order to marry then-Princess Elizabeth, Philip has often played the role as mediator within the family. When Diana joined the family, he reportedly felt for his daughter-in-law’s stressful situation. Then, when Diana and Charles’ marriage was imploding, Philip wrote Diana many letters offering his help and also told the princess that no one in the family understood how Charles could choose Camilla Parker Bowles over her. When Harry got engaged to Meghan, Philip reportedly went out of his way to make his future granddaughter-in-law feel welcome. In 2018, despite having had a full hip replacement just a few month before Harry and Meghan’s wedding, the Duke was determined to attend the ceremony. He walked into Windsor Chapel without assistance looking healthy and in good spirits. “There was nothing that was going to keep him away from the wedding,” said a royal source. “It was important to him and he knew how important it was to Harry.” And for more on the Sussexes’ year ahead, check out The One Thing Meghan and Harry Are Really Looking Forward to in 2021. When Harry and Meghan announced they were stepping down from their senior royal roles, an insider told Best Life at the time the Duke of Edinburgh went from “furious to deeply saddened.” The royal source revealed, Philip was “seething with anger” at first, asking, “Bloody h***, what do they think they’re doing?” In fact, he was so incensed when the Sussex Summit was taking place at Balmoral in 2020 that he insisted on being driven off the estate while the Queen, Charles, William, and Harry were left to negotiate Megxit. Philip was hospitalized last week when the news broke that the Sussexes were not coming back into the royal fold and the Queen had stripped Harry of his titles and patronages. He would have undoubtedly been upset by the Sussexes’ response. “The Duke of Edinburgh spent 64 years in service to the crown,” a source told Best Life. “The shocking way Harry has chosen to respond to the Queen’s decision after all the attempts Her Majesty made to keep him and Meghan in the family would no doubt cause Philip great distress. He is a loving grandfather, but his first loyalty is to the Queen and the monarchy.” And for more on the future of the House of Windsor, check out Can the Monarchy Survive Without Queen Elizabeth? Diane Clehane is a New York-based journalist and author of Imagining Diana and Diana: The Secrets of Her Style.