The Military timeline of Denmark is centered around an involvement in wars in Northern Europe since 793 and, recently, elsewhere. In the early Middle Ages, Danish Vikings invaded and conquered parts of the British Isles and Normandy. Later in the Middle Ages, Denmark was repeatedly in combat with Scandinavian neighbours and in the Baltic area. The "Union Wars" of the 15th and early 16th centuries took place between Denmark and Sweden, then united in the Kalmar Union. After Sweden broke away, Denmark – until 1814 remaining united with Norway – again confronted Sweden in the Northern Seven Years' War (1563–70) and the Kalmar War (1611–13). 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. The eventual defeat of Napoleon led to the break-up of the Denmark-Norway union. The next major combats were over control of Schleswig, in the First and Second Schleswig Wars. The result hereof being that Denmark lost Schleswig, of which the northern part returned in 1920. Denmark remained neutral in World War I, but in World War II the country was occupied, with little fighting, by Nazi Germany in 1940. As a member of the United Nations and NATO, Denmark has participated in military operations since 1992: in Bosnia, Afghanistan, Iraq and Libya.

The Viking Age (793–1050)

Early period

Union Wars (1434–1523)

War with Lübeck and "The Counts Feud" (1534–1537)

War against The Netherlands (1542–1543)

Seven Years' War (1563–1570)

Kalmar War (1611–1613)

Thirty Years' War (1618–1648)

Thorsteinson War (1643–1645)

Northern Wars (Carl Gustav Krigene) (1657–1660)

Scanian War (Skånske Krig) (1675–1679)

Great Northern War (Store Nordiske Krig) (1700–1720)

Rákóczi's War of Independence (1703–1711)

Russo-Swedish War (1788)

Napoleonic Wars (Napeoleonskrigene) (1800–1813)

Gunboat War (Kanonbådskrigen) (1807–1814)

First War of Schleswig (Treårskrigen / Første Slesvigske Krig) (1848–1850)

Second War of Schleswig (Krigen i 1864 / Anden Slesvigske Krig) (1864)

German Occupation (Den tyske besættelse) (1940–1945)

Operations in Bosnia (1994)

War in Afghanistan (2001–2021)

Invasion of Iraq (2003)

Military intervention in Libya (2011)