Vigil of the Princes
The Vigil of the Princes is the unofficial name given to two occasions when male members of the British Royal Family have stood guard during the lying in state of one of their relatives during or as part of a British state funeral or ceremonial funeral.
King George V 
King Edward VIII, Prince Albert, Duke of York, Prince Henry, Duke of Gloucester, and Prince George, Duke of Kent, took guard on 27 January 1936 at the lying-in-state of their father, King George V. The vigil took place after Westminster Hall was closed to the public for the evening.
No photographic record of this event exists, though a painting was made of it after the King's funeral. The oil painting was produced by Frank Beresford as the official painting of the King's lying-in-state, and was exhibited for the first time at the Royal Academy exhibition of 1936 at Burlington House. The painting, named "The Princes' Vigil: 12.15am, January 28 1936", was subsequently purchased by Queen Mary to give to her son Edward VIII on his birthday. Prince Henry is seen depicted in the 10th Royal Hussars uniform, Prince George is in Royal Navy uniform and the King in Grenadier Guards uniform.
Queen Elizabeth The Queen Mother 
The Prince of Wales, the Duke of York, the Earl of Wessex and Viscount Linley took guard at 16:40 UTC on 8 April 2002 at the lying-in-state of their grandmother, Queen Elizabeth The Queen Mother (consort of King George VI; daughter-in-law of King George V). The four relieved the guard of the Royal Company of Archers, and were themselves relieved by the Yeomen of the Guard after their twenty-minute vigil. Both the Prince of Wales and the Duke of York wore naval uniform, while the Earl of Wessex and Lord Linley wore morning dress; the Earl of Wessex served in the Royal Marines, but chose to leave before graduation, while Lord Linley has never served in the forces. Present during the Changing of the Guard were the Prince of Wales' two sons, Prince William and Prince Harry.