Her Majesty The Queen sadly passed away at Balmoral Castle on September 8 at the age of 96.
Her funeral took place today at Westminster Abbey in central London with over 2,000 guests in attendance as they pay their respects to Britain's longest reigning monarch.
The Abbey has held many momentous occasions over the years, including Queen Elizabeth's coronation back in 1953 and the Queen Mother's funeral in 2002.
One of the most recognisable graves, placed at the west entrance of Westminster Abbey, is the grave of the Unknown Warrior.
But who was the Unknown Warrior and what is the story behind the grave?
Who was the Unknown Warrior?
According to the Westminster Abbey website, the Unknown Warrior's body was brought from France to be buried at the Abbey on November 11, 1920.
The grave contains the remains of an unidentified British serviceman who was interred in 1920 as a way of honouring the fallen of the First World War.
The grave, which contains soil from France, is covered by a slab of black Belgian marble from a quarry near Namur.
What is the story behind the Unknown Warrior?
The selection of the Unknown Warrior was a secretive event and remains a mystery to this day to symbolise all those who had died for their country, but whose place of death was not known, or whose body remained unidentified.
The idea of the grave came from the Reverend David Railton (1884-1955), when he noticed in 1916 in a back garden at Armentières, a grave with a rough cross on which were pencilled the words "An Unknown British Soldier".
In August 1920 the Reverend wrote to the Dean of Westminster, Herbert Ryle, who then conducted the memorial.
The body was chosen from unknown British servicemen exhumed from four battle areas, the Aisne, the Somme, Arras and Ypres.
What happened at the burial?
The coffin for the Unknown Warrior was made of two-inch thick oak from a tree which had grown in Hampton Court Palace garden and it was lined with zinc.
It was covered with the flag that David Railton had used as an altar cloth during the War, which is known as the Ypres or Padre's Flag and it now hangs in St George's Chapel, Windsor Castle.
On the same day as the burial, the unveiling of the Cenotaph in Whitehall took place.
King George V placed a wreath of red roses and bay leaves on the coffin and his card read "In proud memory of those Warriors who died unknown in the Great War. Unknown, and yet well-known; as dying, and behold they live. George R.I. November 11th 1920".
George R. I stands for George Rex. Imperator, meaning King and Emperor of India.
Burial attendees included Queen Alexandra, the queens of Spain and Norway, the Duke of Connaught, politicians Lloyd George and Asquith, and Sir Douglas Dawson.
Can you visit the grave of the Unknown Warrior?
The grave of the Unknown Warrior is placed in the west entrance of Westminster Abbey and it can be seen by members of the public when the Abbey is open.
Westminster Abbey is currently closed for the state funeral of Queen Elizabeth II and according to its website, it will reopen on Wednesday, September 21, and Thursday, September 22, between 9.30am and 3.30pm.
You can leave your tributes to Queen Elizabeth II here