D-Day landings: Soldier speaks to his great-grandchildren about Normandy landings

Today is the 75th anniversary of one of the biggest invasions during World War Two.

The D-Day landings marked the start of the campaign to free north-west Europe from the Nazis.

It was a really important moment during the war and is known as D-Day.

Newsround has been to meet two children whose great-grandad - 99-year-old Don Sheppard - fought on that day.