Seventy-five years ago, a young British sailor stood on the bridge of a warship, its gun barrels pointing out to the coast of France, and watched the devastation being rained down on a country he wanted to liberate.

Today, Richard Llewellyn, 93, is among the dwindling number of veterans of the Allied D-Day invasion of Normandy — an operation that turned the tide of World War II and marked the beginning of the end of the conflict.

The invasion of France is usually told as the story of brave, young men struggling across beaches and fighting their way inland. However, another battle unfolded at sea that day, between the Allied ships and the massive German coastal guns.