Sand artists will also create giant portraits of people killed in the war, which will be washed away by the incoming tide, Boyle announced Friday.

The beachside commemoration caps four years of British cultural activities marking the centenary of the 1914-18 conflict, in which 20 million people died.

Boyle said beaches "are truly public spaces, where nobody rules other than the tide."

"They seem the perfect place to gather and say a final goodbye and thank you to those whose lives were taken or forever changed by the First World War," he said.

The "Trainspotting" and "Slumdog Millionaire" director stepped down earlier this year from the helm of the next James Bond film over what producers said were creative differences. He has been replaced by Cary Fukunaga.

Boyle said giving up the 007 job had helped create more time to work on the World War I project.

"I was absolutely desperately keen to do this," said Boyle, who also directed the 2012 London Olympics opening ceremony. "My involvement in it would have been slightly compromised by that workload.

"But I was still very, very keen to do it because it's a real, proper privilege to do something like this where you hope to connect with everybody in the country in some way, as much as you can, rather than through your normal channels, like the box office."