No one knows. Legend says it fell from the sky.
Dannebrog
Red flag with a white cross
Unfortunately it is not the Danish flag, but a crusader flag. The flag in the Church is not only a flag, it is a Royal or a flag the government use, when there is something to celebrate in the Royal family or visiting from other states. All official buildings use it in that case.
Is small
The oldest flag still used by a nation, is the danish flag Dannebrog.
It is the oldest NATIONAL flag still in use - it is not the oldest flag.
According to the myth, the Danish flag (called Dannebrog) fell down from the sky to Valdemar II during the battle of Lyndanisse the 15 June 1219.
The first U.S. flag was designed in 1777.
The flag of the U.S.V.I was designed by Mitch Davis.
The person that designed the Brazilian flag is Decio Vilares.
The flag was designed at the request of King Kamehameha I.
Old. It's from the beginning of 1200's.