The Danish flag's red background represents courage, while the white of the cross stands for peace.
The world's oldest flag still in use, the Dannebrog, is celebrating turning 800 years old at a ceremony at Vordingborg, from where Danish ships under Valdemar the Great set sail.
The Danish flag's red background represents courage, while the white of the cross stands for peace. Mayor of Vordingborg Seiding Larsen said: "That says something about us as Danish people that we want peace, but we have to do it with courage. To do and to find peace everywhere."
Archaeologist Nanna Holm explained the historical significance of the cross, saying: "There have been flags from before Christianity, but what we see here in Medieval Europe is that, we are now united under the cross. We have to take in the world in Jesus or in God's name and therefore you see these crosses appear on everybody's flags."
Denmark's Crown Prince Frederik and Crown Princess Mary turned out to see the flag ceremonially hoisted.
Visitor Anne Vollen Rafn said: "I think it bonds us together. Keeps us stronger. And it also bonds all the newcomers to the country as well. So they can get bound into our traditions and feel like a part of the country they live in."