In the late 9th century, warriors led by the Norwegian Viking chieftain Hardegon conquered the Jutland peninsula. The Danish monarchy, which claims to be the world's oldest, dates back to Hardegon's son, Gorm the Old, (Danish mums had a few problems naming their children), who established his reign early in the 10th century. Gorm's son, Harald Bluetooth, completed the conquest of the Danes, speeding their conversion to Christianity. Bluetooth's gob-stopping successors, Forkbeard and sons got the wood on England, setting up shop and throne and living the sweet life of Anglo-Dane monarchs. They kept it together for half a century or so, but as Viking power waned, the borders of the Danish kingdom shrank back to Denmark.

Blackadderish strife, plots, counter plots and assassinations marked the medieval period. By the late 14th century, upstart dynasties intermarried, eventually forming the Kalmar Union under fair Queen Magrethe; Denmark, Norway and Sweden, now all bunked in together, started to exasperate each other. Sweden was particularly peeved by profligate Danish spending on wars, and the union dissolved in 1523 when Sweden elected Gustav Vasa as its king. Norway, however, was to remain under Danish rule for another three centuries.

In the 16th century the Reformation swept through the country, leaving burnt churches and civil warfare in its wake. The fighting ended in 1536 with the ousting of the powerful Catholic church and the establishment of a Danish Lutheran church headed by the monarchy. King Christian IV ruled for the first half of the 17th century, undermining fabulous trade and wealth creation by leading his subjects into the disastrous Thirty Years War with Sweden. Denmark lost land and money and the king an eye. Even more disastrous were the losses to Sweden incurred some decades later by Christian's successor, King Frederick III. Denmark emerged slowly from these wars, focusing on civil development and reform.

During the Napoleonic Wars Britain attacked Copenhagen twice, inflicting heavy damage on the Danish fleet in 1801 and leaving much of Copenhagen ablaze in 1807. The Swedes then took advantage of a weakened Denmark, successfully demanding that Denmark cede Norway to them. The 19th century might have started off lean, dismal and dominated by a small Frenchman with a big ego, but by the 1830s Denmark had awakened to a cultural revolution in the arts, philosophy and literature. A democratic movement in Denmark led to the adoption of a constitution on 5 June 1849, which in turn led to the formation of a Danish constitutional monarchy. Germany took control of Schleswig in southern Jutland, after its inhabitants, people of both Danish and German heritage, revolted against the new constitution.

Neutral in WWI, Denmark reaffirmed its neutrality at the outbreak of WWII; but, on 9 April 1940, with German warplanes flying over Copenhagen, Denmark surrendered to Germany. The Danes were able to cling to a degree of autonomy, but after three years the Germans ended the pretence and took outright control. Although the island of Bornholm was heavily bombarded by Soviet forces, the rest of Denmark emerged from WWII relatively unscathed. Under the leadership of the Social Democrats a comprehensive social welfare state was established. Denmark is still providing its citizens with extensive cradle-to-grave security. An election in November 2001 brought a centre-right, conservative coalition to power with a campaign that focussed on immigration. Fears generated in the wake of the September 11 terrorist attacks on the USA were an important factor.

Although Denmark voted to join the European Community (now the European Union) in 1973, the Danes have been hesitant to support expansion of the European Union (EU). Indeed, when the Maastricht Treaty, which established the terms of a European economic and political union, came up for ratification in Denmark in June 1992, Danish voters rejected it by a margin of 51% to 49%. After being granted exemptions from the Maastricht Treaty's common defence and single currency provisions, the Danes, by a narrow majority, voted to accept the treaty in a second referendum held in May 1993. In September 2000 the Danes signalled a deeper discontent with European intigration when they rejected adoption of the euro, despite strong support for the pan-European currency by the government and business leaders.

When Norway broke its political ties with Denmark in the early 19th century, the former Norwegian colonies of Iceland, Greenland and the Faroe Islands stayed under Danish administration. Iceland, under Danish rule since 1380, declared itself an independent state in 1918, although foreign policy was still controlled from Copenhagen. Iceland became completely independent in 1944. The Kingdom of Denmark still includes Greenland and the Faroe Islands, but both are essentially self-governing. The Faroe Islands has had home rule since 1948, Greenland since 1979. In part because Denmark retains responsibility for their banking, defence and foreign relations, Greenland and the Faroe Islands each have two parliamentary representatives in the Danish Folketing. Unlike Denmark, however, neither Greenland nor the Faroe Islands is part of the EU.