Czech Republic & Czechoslovakia

Flag of Czechoslovakia and the Czech Republic, adopted in 1920. It was the official flag for the First Czechoslovak Republic/Republic of Czechoslovakia (1918-1938), the Second Czechoslovak Republic (1938-1939), the Third Czechoslovak Republic (1945-1948), the Czechoslovak Socialist Republic (1948-1990), the Czech and Slovak Federative Republic (1990-1992) and the modern Czech Republic.

Original Flag:
https://upload.wikimedia.org/wikipedia/commons/thumb/2/2d/Flag_of_Czechoslovakia.svg/640px-Flag_of_Czechoslovakia.svg.png

Kingdom of Bohemia (Russian client state)

Flag of the Kingdom of Bohemia as a Russian client state. From Kaiserreich.

Kingdom of Czechs, Moravs and Slovaks

Flag of the Kingdom of the Czechs, Moravs and Slovaks. From Kaiserreich.

Kingdom of Bohemia (with Czech Republic Coat of Arms)

Flag of the Kingdom of Bohemia with the Czech Republic's Coat of Arms. In Kaiserreich canon, it is called the Kingdom of Czechs and Moravs.

Kingdom of Bohemia with Coat of Arms.

Flag of the Kingdom of Bohemia with the Bohemian Coat of Arms.