The flag was banned by the Nazis in 1939 as they established a government nominally in control of Bohemia and Moravia, and a horizontal tricolour of white, red, and blue was used for the duration of the war.

The traditional colours of the Czech lands originated from an 1192 coat of arms (depicting a rampant lion with a double silver tail on a field of red).

[1] His design included the red and white horizontal stripes derived from the coat of arms of Bohemia and added a blue chevron extended halfway.

[2] Additionally, during a short period following the Velvet Revolution, between 1990 and 1992, the Czech part of the Czechoslovak federated state adopted the previous red and white flag.

The flag is formed from an isosceles triangle that extends halfway along the rectangle (a common mistake is to draw it shorter) and two bands: one white and one red.