State visit of the President of Ireland to the United Kingdom with full cavalry escort to Windsor Castle, where the President, accompanied by the Duke of Edinburgh, inspected a Guard of Honour provided by the 1st Battalion Irish Guards. President Higgins presented a ceremonial red coat to its regimental mascot, an Irish Wolfhound called Domhnall of Shantamon. The President viewed Irish-related items from the Royal Collection at Windsor Castle. Afterwards they departed for London and visited Westminster Abbey for a tour, where the President laid a wreath at the Grave of the Unknown Warrior and paid his respects with a bow to the tomb of Louis, the Earl of Mountbatten. After
The Unknown Warrior the Medal of Honor, from the hand of General John Pershing; it hangs on a pillar close to the tomb. On 11 November 1921, the American Unknown Soldier was reciprocally awarded the Victoria Cross. When Elizabeth Bowes-Lyon married the future King George VI on 26 April 1923, she laid her bouquet at the Tomb on her way into the Abbey, as a tribute to her brother Fergus who had died at the Battle of Loos in 1915 (and whose name was then listed among those of the missing on the Loos Memorial, although in 2012 a new headstone was erected