05/08/2014 12:37 BST | Updated 05/08/2014 15:59 BST

First World War Centenary Marked By Extraordinary Tower Of London Poppy Field (PICTURES)

Kate Middleton, Prince William and Prince Harry paid a visit to one of the most ambitious and complex art projects to mark the centenary of the First World War.

The royals added a ceramic poppy today to the Tower of London's 'Blood Swept Lands and Seas of Red' poppy installation - by artist Paul Cummins - which commemorates the 100th anniversary of the outbreak of war.

The installation uses hundreds of thousands of the poppies to represent blood sweeping into its moat and was officially unveiled today.

The final poppy will be planted on November 11 - Armistice Day and there will be 888,246 of them planted, with each representing a Briton killed on military service during the four-year war.

Photo gallery The Tower Of London Poppy Field See Gallery