Flag of Finland in the context of Finnish national identity

The Kingdom of Finland (Finnish: Suomen kuningaskunta; Swedish: Konungariket Finland; 1918–1919) was a failed attempt to establish a monarchy in Finland in the aftermath of the Finnish Declaration of Independence from Russia in December 1917 and the Finnish Civil War from January to May 1918. The victorious Whites in the Parliament of Finland began the process of turning Finland into a kingdom and creating a monarchy. Although the country was legally a kingdom headed by a regent for over a year, the king-elect Friedrich Karl never reigned nor came to Finland following Germany's defeat in World War I. Republican victories in subsequent elections resulted in the country becoming a republic.

During the Finnish Civil War of 1918, Finnish Reds on friendly terms with Soviet Russia fought Finnish Whites who allied with the German Empire. Direct aid from the German Baltic Sea Division helped the Whites win the war. The provisional government established after the Grand Duchy of Finland's declaration of independence leaned heavily toward the Finnish right and included a number of monarchists. The parliament drew up plans to create a Finnish monarchy on the legal theory that the Swedish Constitution of 1772 was still in effect, but there had been an extended interregnum with no monarch on the throne. Prince Friedrich Karl of Hesse was elected to the throne of Finland on 9 October 1918 by the Finnish parliament, but he never took the position nor traveled to Finland. Soon after the election, Finnish leaders as well as the population belatedly came to understand the grave situation their German allies were in, and the wisdom of electing a German prince as monarch as Germany was about to lose World War I was called into question. Germany itself became a republic, deposed Kaiser Wilhelm II and signed an armistice with the Allies in November. The victorious powers informed the Finnish government that the independence of Finland would only be recognized if it abandoned its alliance with Germany. As a result, Friedrich Karl renounced the throne in December and the Baltic Sea Division withdrew from Finland. In the March 1919 election, with the Finnish left and socialists able to vote, republicans won a crushing victory. Finland's status as a republic was confirmed in the Finnish Constitution of 1919.

Flag flying days in Finland are days of the year when the national flag is flown nationwide, either by law or by custom. The flag of Finland is generally flown only on special occasions to celebrate or honour someone or something. On certain days of the year the state officially flies the flag, and recommends all private citizens to do so as well, these are the flag flying days as listed below. Any citizen has a right to fly the flag on their own property if they deem it appropriate, for example in celebration of birthdays or weddings in the family. Midsummer's day is additionally celebrated as Flag Day in Finland.

A Nordic cross flag is a flag bearing the design of the Nordic or Scandinavian cross, a cross symbol in a rectangular field, with the centre of the cross shifted towards the hoist.

All independent Nordic countries have adopted such flags in the modern period, and while the Nordic cross is named for its use in the national flags of the Nordic nations, the term is used universally by vexillologists, in reference not only to the flags of the Nordic countries but to other flags with similar designs. The cross design represents Christianity, and was first seen in the Dannebrog, the national flag of Denmark in the first half of the 13th century. The same design, but with a red Nordic cross on a yellow background, was used as union flag during the Kalmar union (1397 to 1523), and when that union fell apart in 1523 the same design, but with a yellow cross on a blue background (derived from the Swedish coat of arms adopted in 1442), was adopted as national flag of Sweden, while Norway adopted their flag in 1821. After gaining independence the other Nordic countries adopted national flags of the same design, Iceland in 1915 and Finland in 1918. The Norwegian flag was the first Nordic cross flag with three colours. All Nordic flags may be flown as gonfalons as well.

Half-mast or half-staff (American English) is the placement of a flag below the summit of a ship mast, a pole on land, or a pole on a building. In many countries this is seen as a symbol of respect, mourning, distress, or, in some cases, a salute.

The tradition of flying the flag at half-mast began in the 17th century. According to some sources, the flag is lowered to make room for an "invisible flag of death" flying above. However, there is disagreement about where on a flagpole a flag should be when it is at half-mast. It is often recommended that a flag at half-mast be lowered only as much as the hoist, or width, of the flag. British flag protocol is that a flag should be flown no less than two-thirds of the way up the flagpole, with at least the height of the flag between the top of the flag and the top of the pole. It is common for the phrase to be taken literally and for a flag to be flown only halfway up a flagpole, although some authorities deprecate that practice.