Sweden

The national flag of Sweden (Swedish: Sveriges flagga) consists of a yellow or gold Nordic cross (i.e. a horizontal cross extending to the edges, with the crossbar closer to the hoist than the fly) on a field of light blue. The Nordic cross design traditionally represents Christianity. The design and colours of the Swedish flag are believed to have been inspired by the present coat of arms of Sweden of 1442, which is blue divided quarterly by a cross pattée of gold, and modelled on the Danish flag. Blue and yellow have been used as Swedish colours at least since Magnus III's royal coat of arms of 1275. (Source: Wikipedia.org, CC BY-SA)

Switzerland

The national flag of Switzerland (German: Schweizerfahne; French: drapeau de la Suisse; Italian: bandiera svizzera; Romansh: bandiera da la Svizra) displays a white cross in the centre of a square red field. The white cross is known as the Swiss cross or the federal cross. Its arms are equilateral, and their ratio of length to width is 7:6. The size of the cross in relation to the field was set in 2017 as 5:8. The white cross has been used as the field sign (attached to the clothing of combatants and to the cantonal war flags in the form of strips of linen) of the Old Swiss Confederacy since its formation in the late 13th or early 14th century. Its symbolism was described by the Swiss Federal Council in 1889 as representing 'at the same the Christian cross symbol and the field sign of the Old Confederacy'. As a national ensign, it was first used during the Napoleonic Wars by general Niklaus Franz von Bachmann, and as regimental flag of all cantonal troops from 1841. The federal coat of arms (eidgenössisches Wappen) was defined in 1815 for the Restored Confederacy as the white-on-red Swiss cross in a heraldic shield. The current design was used together with a cross composed of five squares until 1889, when its dimensions were officially set. (Source: Wikipedia.org, CC BY-SA)

Turkey

The national flag of Turkey, officially the Turkish flag (Turkish: Türk bayrağı), is a red flag featuring a white star and crescent. The flag is often called 'the red flag' (al bayrak), and is referred to as 'the red banner' (al sancak) in the Turkish national anthem. The current Turkish flag is directly derived from the late Ottoman flag, which had been adopted in the late 18th century and acquired its final form in 1844. The measures, geometric proportions, and exact tone of red of the flag of Turkey were legally standardized with the Turkish Flag Law on 29 May 1936. (Source: Wikipedia.org, CC BY-SA)

Ukraine

The flag of Ukraine (Ukrainian: Прапор України, romanized: Prapor Ukrainy) consists of equally sized horizontal bands of blue and yellow. As a national flag, the blue and yellow bicolour has been used since the 1848 Spring of Nations, when it was hoisted over Lviv Town Hall. It was officially adopted as a state flag for the first time in 1918 by the short-lived West Ukrainian People's Republic and subsequently used by the Ukrainian People's Republic, just before World War II it was also adopted by Carpatho-Ukraine in March 1939. When Ukraine was part of the Soviet Union, the flag of the Ukrainian Soviet Socialist Republic was used and the bicolour flag was outlawed. The blue and yellow flag was provisionally adopted for official ceremonies in September 1991 following Ukrainian independence, before officially being restored on 28 January 1992 by the Parliament of Ukraine. Ukraine has celebrated the Day of the National Flag on 23 August since 2004. (Source: Wikipedia.org, CC BY-SA)

United Kingdom

The national flag of the United Kingdom is the Union Jack, also known as the Union Flag. The design of the Union Jack dates back to the Act of Union 1801 which united the Kingdom of Great Britain and the Kingdom of Ireland (previously in personal union) to create the United Kingdom of Great Britain and Ireland. The flag consists of the red cross of Saint George (patron saint of England (which also represents Wales)), edged in white, superimposed on the saltire of St Patrick (patron saint of Ireland), also edged in white, which are superimposed on the saltire of Saint Andrew (patron saint of Scotland). Wales is not represented in the Union Flag by Wales's patron saint, Saint David, because the flag was designed whilst Wales was part of the Kingdom of England. (Source: Wikipedia.org, CC BY-SA)

Vatican City

The flag of Vatican City was adopted on 7 June 1929, the year Pope Pius XI signed the Lateran Treaty with Italy, creating a new independent state governed by the Holy See. The Vatican City flag is modeled on the 1808 yellow and white flag of the earlier Papal States, to which a papal tiara and keys were later added. The Vatican (and the Holy See) also refers to it, interchangeably, as the flag of the Holy See. The flag consists of two vertical bands, one of gold or yellow (hoist side) and one of white with the crossed keys of Saint Peter and the Papal Tiara centered in the white band. The crossed keys consist of a golden and a silver key, in which the silver key is placed in the dexter position. Despite the widespread idea that the flag is square, its proportions are not specified in the constitution, and in response to a letter sent in this regard, the nunciature in Germany explicitly mentioned that the flag is not square. (Source: Wikipedia.org, CC BY-SA)