Kate Middleton, Prince William & Prince Harry Honors Fallen WWI Soldiers, Camilla Parker-Bowles Celebrates the Centenary in Westminster Abbey [PHOTOS]

Celebrating a century since Britain's entry into the First World War in Belgium, Prince William and Kate Middleton attended a ceremony in Liege to mark the 100 years since the country was invaded by Germany. Representing Queen Elizabeth, the royal couple were joined by dignitaries from countries across Europe, including France, Austria and Germany, for a ceremony at the Allies' Memorial at Cointe.

Prince Harry joined the Duke and Duchess of Cambridge, including Prime Minister David Cameron, at a twilight ceremony at St Symphorien Military Cemetery. Leading the moving tributes at the ceremony, 29-year-old royal "remember the fallen of the First World War with a poignant letter home from an Irish Fusilier, written weeks before he was killed at Gallipoli."

"The moving letter was sent by Private Michael Lennon, of 1st Battalion the Royal Dublin Fusiliers. Dated May 30, 1915 - it was written to his brother Frank, the day before he was due to land in Gallipoli," according to Daily Mail.

The soldier wrote: Well Frank, I suppose we are for it tomorrow, if we don't get shelled on the way.

"I can only hope that we have all the luck to come through the night and if I should get bowled out - well it can't be helped."

Lennon was killed almost one month later and never got the chance to see Dublin again.

British actor Eddie Redmayne, star of "Les Misrables," was also there to commemorate the event as he read from A Shropshire Lad and joined the choirs from Britain and Germany as they sang the song "They Shall Not Grow Old."

The Duke and Duchess of Cambridge also took some time to visit the Tower of London with Prince Harry and were joined by the Constable of the Tower of London, General Lord Dannatt, and his wife Philippa. During her tour in the impressive poppy installation, dubbed as "Blood Swept Lands And Seas of Red," Kate was overcome with her emotion and shed a tear as she buried the handmade poppy on the ground.

Meanwhile, in another side of the country, Camilla Parker-Bowles celebrated the World War I centenary at Westminster Abbey. Accompanied by Dean of Westminster the Reverend John Hall, the Duchess of Cornwall attended a candlelit vigil and prayer service to honor those who lost their lives during the Great War.