In 1944 thousands of ships set off from the coast of southern England, part of a huge sea, air and land assault on Nazi-occupied France.
Most of the troops were from Britain, Canada and America.
Well, now, not many surviving veterans are able to make the journey back to the beaches to attend commemorative events.
One veteran, though, lives just a few hundred yards from the German pill-box he stormed back then.
Derek Johnson went to meet him ahead of today's D-Day anniversary.
Derek spoke to Leon Gautier, D-Day veteran.