On April 18, one of the military dates is celebrated in Denmark - the anniversary of the Battle of Dybbel (Dan. Slaget ved Dybbøl). In honor of this event, the state flag is raised in the country and solemn events are held.
Military flag days (holidays and memorable dates, in honor of which the national flag of Denmark is raised in places established by law), allocated in a separate group, refer to various periods of wars between Denmark and its nearest and distant neighbors.
On April 18, 1864, during the Danish-Prussian War (Second War of Schleswig), the Danish troops were defeated near the city near Dyubbel. During this battle, about 4,800 Danes and about 1,200 Prussians were killed, wounded or captured.
As a result, on October 30 of the same year, a peace treaty was signed in Vienna. Denmark renounced its claims to Lauenburg, Schleswig and Holstein. The duchies were declared joint possessions of Prussia and Austria.
By the way, in addition to the Battle of Dyubbel, flag days in Denmark are other battles of the 1864 war with Prussia and Austria for the redistribution of the borders of Schleswig: the Battle of Mysunde (February 2) and the Battle of Helgoland (Battle at Helgoland, May 9).