With or without a hyphen, the name of the Slovaks' and Czechs' joint country was modeled on the name of the Habsburg Empire designed in 1867 – Austria-Hungary. That new name for the Habsburg lands symbolized that the monarchy would be constituted of two parts with two equal state legislatures, one in Vienna and one in Budapest. The finance, defense, and foreign policy remained centralized.



CS 1930

1919 (- ca. 1925)



CS 1938



SK 1942

1939 Slovakia
(CS does not exist)


CS 1975




SK 2010

1993 Slovakia
(CS does not exist)


International hyphen


A French poster for the 1920 Czech film, The Temple Builder.

World War I

When Slovak-American and Czech-American activists drew up the first agreement to work towards the creation of a joint country for the two neighboring Slavic peoples in the Habsburg Empire, their English-language Cleveland Agreement of 1915 spelled it Czecho-Slovakia, and so did their final such treaty, the Pittsburgh Agreement, drafted and signed by the country's future president Tomáš Garrigue-Masaryk in 1918. He also hyphenated the name of its future citizens as Czecho-Slovaks in several of his works, as he did in the Philadelphia Declaration he signed on 26 October 1918.

The action group set up by Masaryk in 1915 as a direct offshoot of the Cleveland Agreement first called itself the Czech Committee Abroad.

It generally used the unhyphenated form after it renamed itself to the Czechoslovak National Committee the following year when it also co-opted the Slovak-French General Milan Rastislav Štefánik as the future country's designated Secretary of War.

The Committee's name eventually changed to the Provisional Government of the Czechoslovak State. The Committee-cum-Provisional Government operated only outside of Austria-Hungary. It presented its "Declaration of Independence of the Czechoslovak Nation" to the U.S. State Department and Allies about 11 days before Czech and Slovak activists made their proclamations in Prague and Martin.

The U.S. press reports on the committee's activities kept its one-word spelling, but the hyphenated spelling cropped up in other U.S. newspaper reports from time to time.

Czecho-Slovakia or Czechoslovakia

Q: What spelling is correct?

The international treaties that formalized the creation of the new country after World War I spelled it Czecho-Slovakia, but the official spelling changed several times after that.

1919 Original hyphenation

With the Habsburgs, and effectively Austria, deposed as role-players after World War I, the existence of the new country was formalized by two treaties – between the victorious Allies (Britian, France, Italy, U.S.) and Germany in 1919 (Treaty of Versailles), and between the Allies and Hungary in 1920 (Treaty of Trianon). Their French, German, Czech, and other legal versions all hyphenated the name as "the Czecho-Slovak State."

The two Central European proclamations that emerged before the nascent government had control over the new country differed in how they spelled it. The Czech Prague "Bill on the Establishment of the Independent Czechoslovak State" of 28 October 1918, supported by four Slovaks whom its organizers managed to trace in Prague, spelled it as one word. The Slovak Martin "Declaration of the Slovak Nation" of 30 October 1918 did not refer to the new country directly, but demanded complete independence for "the Czecho-Slovak nation" having described "the Slovak nation" as its constituent part.

Tellingly, the first Provisional Constitution adopted in Prague two weeks later achieved the tough feat of not mentioning the name of the country it constituted at all.

But the new country's stamps issued on
18 December 1918 used hyphenation, the Czecho-Slovak Post Office, and Prague kept the hyphenation for a time in some of its instruments intended for foreign governments, in order to match the spelling in the treaties that created the country.

Dropped hyphenation

Internally, though, Prague had already dropped the hyphen before the second international treaty was signed. The change to Czechoslovakia was indirectly formalized with the adoption of the first Constitution on 6 March 1920, which contained the unhyphenated spelling, although the hyphen continued to occur intermittently in the country's diplomatic documents for several more years. While the hyphen did not disappear completely from the Slovak press in the new country, the unhyphenated spelling prevailed. The hyphen remained more common in the Slovak-American press.

1938 Restored hyphenation

Prague, weakened after the border areas of the country's western part were absorbed by Germany, restored the hyphenated spelling under pressure from several Slovak parties on 6 October 1938 when Slovakia became an autonomous region of Czecho-Slovakia, but either spelling was rendered irrelevant 1938hyph250 within months. A week after the stamp to commemorate the late President Masaryk was issued with the hyphenated Czecho-Slovakia in 1939, Slovakia became a country, while the Czech-speaking territories were turned into a province in Germany.

1945 Dropped hyphenation

When the Czech-speaking territories were rejoined with Slovakia after World War II, the hyphen was dropped once more. Its informal use was then disallowed by the communists after their takeover in 1948.

1990 Dual spelling

After the collapse of communism, the formal name of the country was changed to the Czech and Slovak Federal Republic in 1990 in order to get around the different spellings in the country's two official languages – the hyphenated spelling was restored in Slovak, the spelling mandated under communism was retained in Czech. Federal documents, whether in Slovak or Czech, used only the country's long formal name.