As Prince William and Prince Harry joined forces to hold a vigil for the Queen in Westminster Hall, eagle-eyed onlookers noticed a tiny – but significant – difference between the two brothers’ outfits. The two brothers stood guard at the Queen’s lie-in-state at Westminster Hall alongside their cousins on Saturday afternoon as a stream of mourners waded in after hours of queuing. Harry, who saw action on the front line during two tours in Afghanistan, has not previously had the chance to don his military uniform as he publicly mourns the fact that he is no longer a working royal. But royal sources said the king decided his youngest son would wear uniform for the vigil. While the gesture seemed kind, one missing detail reportedly left Harry “devastated.” Prince Harry appeared at the vigil in military uniform, but his grandmother’s initials were not on his shoulders. Source: Getty His grandmother’s initials ‘ER’ were removed from the shoulders of the uniform, while still appearing on both of his brother’s shoulders. Before attending the vigil, Harry was reportedly considering wearing a morning suit to avoid “humiliation”, the Times reported. “He’s heartbroken. Removing his grandmother’s initials is very appropriate,” a source told the publication. On Friday night, the Queen’s children – Charles, the Duke of York, Princess Royal and the Earl of Wessex – took part in their own vigil. Prince William and the Duke of York both wore the Queen’s initials on their uniforms at separate vigils. Source: Getty An exception was made for disgraced Andrew, who is no longer a working king, to be allowed to wear his military uniform as a “special mark of respect” for the Queen. At the event, the Queen’s initials can be seen on his shoulders. Despite being a former army officer, Harry has been wearing civilian clothes for official events, including walking behind the Queen’s coffin on Wednesday. The two brothers appeared at the vigil along with their cousins. Source: Getty William and Harry were joined in their silent tribute around the coffin by cousins Zara Tindall and Peter Phillips, Princesses Beatrice and Eugenie and Lady Louise Windsor and her brother Viscount Severn. The Queen’s funeral will take place on Monday 19 September. Her Majesty’s Repose in Westminster Hall will close to the public at 6.30am. The story continues Shortly after 10.35 the coffin will be lifted from the hearse. He will be carried in procession from Westminster Hall in the Royal Navy state carriage, which will then travel to Westminster Abbey for the funeral. The Queen will be buried in St George’s Chapel at Windsor Castle in the afternoon, reuniting with her late husband Prince Philip, Duke of Edinburgh.