ate Middleton, Prince William and Prince Harry visited a poppy art installation at the Tower of London honoring fallen World War I soldiers. Credit: Samir Hussein/WireImage;

Things got emotional for Kate Middleton on Tuesday, Aug. 5. The Duchess of Cambridge visited the Tower of London with her husband Prince William and brother-in-law Prince Harry at an event that honored fallen World War I soldiers on the 100th anniversary of the British Commonwealth's declaration of war on Germany.

Prince George's mum, 32, wore her blue L.K. Bennett "Detroit Dress," which contrasted beautifully against the hundreds of thousands of red ceramic poppies honoring the dead. Both Princes Harry and William wore navy blue suits for the occasion and were joined by the Constable of the Tower of London, General Lord Dannatt, and his wife Philippa.

The art installation, dubbed "Blood Swept Lands And Seas of Red" is comprised of nearly 120,000 ceramic poppies. The sweeping red landscape is expected to be completed by November, where 888,246 flowers in total will be planted—each handmade poppy signifying British soldiers and civilians killed in the war.

The Duchess, during her tour of the special installation, was overcome at one point and wiped away a tear.

Members of the public can each purchase a poppy for £25 (approximately $42) to add to the installation. Proceeds will benefit several military charity organizations.

Their latest visit follows their Monday, Aug. 4, oversea stop in the city of Liege, to honor the people of Belgium. "Belgium's steadfast remembrance of your war dead, and ours, is a great credit to your nation," Prince William said in a speech. "On behalf of Her Majesty Queen Elizabeth, head of the Commonwealth, thank you for the honor you do us all… We were enemies more than once in the last century, and today we are friends and allies. We salute those who died to give us our freedom. We will remember them."