In the early Middle Ages, Danish Vikings invaded and conquered parts of the British Isles and Normandy.
Denmark was heavily involved in the Thirty Years' War (1618–1648) on the side of the Protestants of the German lands.
During the 16th to 18th centuries, Danish military involvement was also directed against Russia and other Eastern European nations in the series of Northern Wars and subsequent campaigns.
Denmark was brought into the Napoleonic Wars on the French side when attacked by Britain at the Battles of Copenhagen in 1801 and 1807.
As a member of the United Nations and NATO, Denmark has participated in military operations since 1992: in Bosnia, Afghanistan, Iraq and Libya.