King Charles paid tribute to Pope Francis as he met with New Zealand's Prime Minister at Windsor Castle on Easter Monday.
While the monarch boasts a quirky collection of ties, Charles, who is head of the Church of England, opted for a sombre black tie as a mark of respect.
New Zealand's premier, Christopher Luxon, also donned a black tie during his Windsor audience.
The pontiff passed away early on Monday morning, aged 88, following a battle with ill health. The Vatican said that he died from a stroke and heart failure.
His death was confirmed via a statement from a senior Vatican official which read: "At 7.35 this morning, the Bishop of Rome, Francis, returned to the home of the Father. His entire life was dedicated to the service of the Lord and of his Church.
"He taught us to live the values of the Gospel with faithfulness, courage, and universal love, especially for the poorest and most marginalised. With immense gratitude for his example as a true disciple of the Lord Jesus, we commend the soul of Pope Francis to the infinite, merciful love of God, One and Triune."
Charles and Camilla's meeting with the pope
King Charles and Queen Camilla met with Pope Francis during their recent state visit to Italy and the Vatican. Following their private audience, an official photo was released, accompanied by the caption: "A special moment for Their Majesties as they privately met His Holiness Pope Francis at the Vatican yesterday.
"The King and Queen were deeply touched by The Pope’s kind remarks about their 20th wedding anniversary and honoured to be able to share their best wishes to him in person."
In the wake of Pope Francis' death, the royal couple issued a heartfelt message in which they expressed their "profound sympathy" and praised his "compassion" as well as his "work and care for both people and planet".
The statement in full read: "My wife and I were most deeply saddened to learn of the death of Pope Francis. Our heavy hearts have been somewhat eased, however, to know that His Holiness was able to share an Easter Greeting with the Church and the world he served with such devotion throughout his life and ministry.
"His Holiness will be remembered for his compassion, his concern for the unity of the Church and for his tireless commitment to the common causes of all people of faith, and to those of goodwill who work for the benefit of others.
"His belief that care for Creation is an existential expression of faith in God resounded with so many across the world. Through his work and care for both people and planet, he profoundly touched the lives of so many.
"The Queen and I remember with particular affection our meetings with His Holiness over the years and we were greatly moved to have been able to visit him earlier in the month.
"We end our most heartfelt condolences and profound sympathy to the Church he served with such resolve and to the countless people around the world who, inspired by his life, will be mourning the devastating loss of this faithful follower of Jesus Christ."