History based on a legend
The legend states that Dannebrog was given to the Danes in Lyndanis (Estonia) in a battle, headed by the Danish King Valdemar the Victorious, conducted to Christianise the heathen. The Danes were losing, but then Dannebrog descended from the skies and landed among the Danes who, when picking it up, suddenly found themselves victorious.
Bishop Anders Sunesen then raised the flag to the sky and thus ensured the Danes their victory over the heathen Estonians who, recognising divine backing, speedily converted to Christianity. The fact that they were threatened with decapitation if they did not convert was not considered of importance by contemporary chroniclers!
This battle took place on June 15, 1219, and to this day we call the 15th of June Valdemar's Day and fly the flag from all public buildings and buses, like we also do on all royal birthdays and during official visits to Denmark by foreign royalty and statesmen.
White cross on a red background
There seems to be, however, an actual historical event behind the legend of the flag. Fighting on the Danish side was a group of German Knights of Saint John, whose banner was precisely the white cross on a red background. Their banner tore itself lose and was carried by the wind up into the air and subsequently landed among the Danish knights. As a kind of thanksgiving for the victory, King Valdemar the Victorious adopted the flag as his private symbol for the Danish army, and soon it became the national flag. The Knights of Saint John also continued using the banner and brought it with them to Malta, where it became the flag of the Maltese Knights.
A popular flag
Unlike in other countries, it is very common in Denmark for ordinary people to fly the flag to signal important events in the family such as birthdays, weddings and the death of a family member, in which case the flag will be flown half-mast.
The name Dannebrog
Dannebrog is, along with the Union Jack, the Tricolore and the Stars and Stripes, one of the few named flags in the world. The name consists of two words: 'Danne' from Old Frisian, meaning 'coloured red', and 'brog', from Old English, meaning 'cloth', related to the word 'breeches', together forming the meaning 'red cloth'.