A red field with a white Nordic cross. The Dannebrog is the world's oldest national flag still in use. By legend, it fell from the sky during the Battle of Lyndanisse in 1219, signalling Danish victory. First documented in the 13th century, formally codified over centuries. Officially celebrated on June 15 — Valdemar's Day — commemorating the 1219 legend. Practise the Denmark flag in the Flagzio Europe flag quiz across all eight game modes.