This graph shows Denmark's total population from the year 1769 until 2020. Generally speaking, Denmark's population has been growing at a rather steady rate for the past 250 years. The numbers begin in 1769 where Denmark's population was approximately 798 thousand; it then grows at a consistent rate for the next 210 years, before the population decreases slightly in the 1980s. This dip in population is attributed to a decrease in the fertility rate across Europe during this time, resulting from improvements and increased access to contraception. The population then begins growing again in the late 1980s, due to a positive net migration rate and ageing population; today, the population is just under 5.8 million people.

During the Second World War, the German invasion of Denmark took place on April 9, 1940, as part of Operation Weserübung. The primary aim of this campaign was the annexation of Norway, as control of the Scandinavian coast protected Germany's iron supply from Sweden and gave a tactical advantage for naval operations against the UK. Heavily outmanned and outgunned, the Danish government surrendered within a few hours, and this was the least-costly German invasion of the war (not including Austria), with just 16 Danish military fatalities on the day. Overall, modern estimates suggest that more than 6,600 Danes died as a direct result of the Second World War. Roughly half of these fatalities were civilian deaths, including upwards of 1,000 sailors killed by German submarines, and over 750 resistance fighters. However a significant share of Danes were also killed in the service of both the Axis or Allied Powers.

Danes in the service of Germany Almost one third of Danish fatalities were in the service of the German military, as over 6,000 Danish military volunteered to join the German war effort on the Eastern Front, alongside an unknown number of ethnic German volunteers (possibly 2,000) from Schleswig, along the German border. Almost 500 Danes were also killed for informing or collaborating with German authorities during the occupation; most of these were killed by the resistance during the occupation, although many were also executed after the war's conclusion.

The Danish resistance and the rescue of Denmark's Jews When compared with resistance movements in other countries, the rapid annexation of Denmark and the non-removal of the Danish government by Nazi authorities resulted in the Danish movement developing more slowly. The Danish government discouraged its citizens from rising up, and the restrictions imposed by Germany were initially less severe than in many other territories. However, resistance groups (including many military personnel) quickly formed and relayed a significant amount of information to the Allies in early years, before their actions became more violent in later years. Alongside numerous sabotage and assassination missions, a major operation of the Danish resistance was the rescue of Denmark's Jewish population. In early September 1943, German diplomat Georg Ferdinand Duckwitz learned of Hitler's order to arrest and deport Denmark's Jewish population, and secretly organized their reception in Sweden, before leaking the information to Danish authorities. Just days before the order was given, the resistance, with aid from Danish authorities, Jewish leaders, and many ordinary citizens, then smuggled over 7,000 Danish Jews and their families to Sweden. Several hundred Danish Jews were ultimately transported to concentration camps, although the majority were eventually rescued by the Danish-Swedish "white bus" missions just before the war's end. More than 99 percent of Denmark's Jews would ultimately survive the Holocaust. Duckwitz was named as one of the Righteous Among the Nations by the Israeli government in 1971, however, the Danish resistance requested not to be honored individually by Yad Vashem as theirs was a collective effort.