One of the biggest names absent from the funeral was Britain's King Charles, who had previously been at the funeral of Pope John Paul II. His son, the Prince of Wales, headed to the Vatican on his behalf, which is common custom for the British royal family.
Charles had represented his late mother, the Queen, at John Paul's funeral in 2005. The move will be seen as a major milestone in William's role as a global statesman and future king.
Although many royal families turned out for the sombre occasion, including those of Jordan and Morocco, the entire Dutch royal family was absent. The reason for their absence is because Willem-Alexander's birthday celebrations, Koningsdag, were being held on the same day.
The celebrations are normally held on 27 April, which is Willem-Alexander's birthday, the only exception is when 27 April falls on a Sunday, which it does in 2025.
Frederik's wife, Queen Mary, represented her husband at the funeral on Saturday. Frederik would have ordinarily attended, however, the Danish monarch was in Japan conducting a state visit and was unable to make it back in time.
Liechtenstein was represented at the Pope's funeral by Hereditary Prince Alois and Hereditary Princess Sophie. It was not confirmed why the heirs attended instead of Prince Hans-Adam.
Take a look back at some of the most memorable and shocking royal stories from the year as the King and Queen and their family navigated some ups and downs
The British monarch shared a rare glimpse inside one of the rooms at Sandringham House and showed the public how the House of Windsor decorates for the festive season