Sophie Raworth visits Fort Southwick in Hampshire, the operation's communications headquarters, where she is joined by a group of Wrens to hear their D-Day memories.
James Holland is given a tour of the miles of secret tunnels under Fort Southwick, Dan Snow explores the Navy's role in D-Day, and two former schoolgirls reveal what life was like as the troops began to arrive in their village.
Veteran Richard Llewellyn shares the details of the diary he kept on D-Day, and Robert Coupe explains how he honours the memory of his fallen comrades by making a very personal modern-day pilgrimage.
