The national flag of Lithuania (Lithuanian: Lietuvos vėliava) consists of a horizontal tricolour of yellow, green, and red.

It was adopted on 25 April 1918 during Lithuania's first period of independence (1918–1940), which ceased with the occupation first by the Soviet Union, and then by Nazi Germany (1941–1944).

The earliest known flags with a Lithuanian identity were recorded in the 15th-century Banderia Prutenorum, written by Jan Długosz.

Until the end of the 18th century, when it was annexed by the Russian Empire, the Grand Duchy of Lithuania used the Vytis as its flag.

[1] The birth of the yellow, green, and red tricolour occurred during a drive by other European republics to change their flags.

[1] It is not known who originally suggested the yellow, green, and red colours, but the idea is usually attributed to Lithuanian exiles living elsewhere in Europe or in the United States during the 19th century.

Artist Antanas Žmuidzinavičius decorated the conference hall with small red and green flags.

[4] However, the delegates decided that the matter should be settled by a special commission, composed of Basanavičius, Žmuidzinavičius, and Daugirdas.

[3] Discussions of the national flag continued; its opponents considered gold an inappropriate colour, since the combination of yellow, green, and red did not follow the existing rules of heraldry.

Two flags were used during the period of Soviet occupation (1944–1988): immediately after the war, the flag consisted of a red field, golden hammer and sickle with the Latin characters LIETUVOS TSR (Lithuanian SSR in the Lithuanian language) above them in gold sans-serif lettering.

[3] Since Lithuania banned Soviet symbols in 2008, raising or otherwise using the Lithuanian SSR flag in public is illegal.

[7] After independence from the Soviet Union, the tricolour flag was written into the new Constitution of Lithuania, which was adopted by a referendum in 1992.

[9] The yellow in the flag is meant to symbolise the sun and prosperity, the green is for the forests, the countryside, liberty, and hope, and the red represents the blood and bravery of those who have died for Lithuania.

Different sizes of the flag can be created, but they must conform to the colour codes and ratio requirements set in the law.

The first method, commonly known as half-staffing, is performed when the flag is hoisted to the top of the flagpole, then lowered to the pole's one-third position.

It is also common to fly the flags of Estonia and Latvia during certain occasions, mainly the celebration of independence of the three Baltic states.

The standard is the coat of arms of Lithuania that supported by griffon and unicorn charged in the center on a single-color background.

[21][22] Each county of Lithuania has adopted a flag, each of them conforming to a pattern: a blue rectangle, with ten instances of the Cross of Vytis (double cross or) appearing in gold, acts as a fringe to the central feature of the flag, which is chosen by the county itself.

In 1938, Dobuzhinsky consulted with Lithuanian philosopher Vydūnas who provided him with information on the historical flag of Lithuania Minor.

According to journalist and collector Vilius Kavaliauskas, "The explanation was simple: the colors of the flag had to match those of the coat of arms.

What is interesting that Smetona was convinced and, possibly on 8 May 1940, he convened a meeting with the Commission of Heraldry where it was decided to change the Lithuanian flag."