With the collapse of Austria-Hungary at the end of World War I, the independent country of CzechoslovakiaEdited by Keith Sword The Times Guide to Eastern Europe Times Book, 1990 p. 53 (Czech, Slovak: Československo) was formed as a result of the critical initiative of the first Czechoslovak president Thomas Masaryk and the intervention of U.S. President Woodrow Wilson, among others.

The Czechs and Slovaks were not at the same level of economic and technological development, but the freedom and opportunity found in an independent Czechoslovakia enabled them to make strides toward overcoming these inequalities.

Political history Historical background to 1918

Although the Czechs and Slovaks speak languages that are very similar, the political and social situation of the Czech and Slovak peoples was very different at the end of the 19th century. The reason was the differing attitude and position of their overlords – the Austrians in Bohemia and Moravia, and the Hungarians in Slovakia – within Austria-Hungary. Bohemia was the most industrialized part of Austria and Slovakia was the most industrialized part of Hungary – however at very different levels of development.

Around the start of the 20th century, the idea of a "Czecho-Slovak" entity began to be advocated by some Czech and Slovak leaders after contacts between Czech and Slovak intellectuals intensified in the 1890s. Despite cultural differences, the Slovaks shared similar aspirations with the Czechs for independence from the Habsburg state.Judit Hamberger, "The Debate over Slovak Historiography with Respect to Czechoslovakia (1990s)," Studia Historica Slovenica 2004 4(1): 165–191Igor Lukes, "Strangers in One House: Czechs and Slovaks (1918–1992)," Canadian Review of Studies in Nationalism 2000 27(1–2): 33–43 In the early stages of World War I, some Western, especially British, writers, such as Charles Ernest Fayle and Robert Seton-Watson, proposed creating and setting up an independent Czechoslovak state in the event of a decisive victory for the Entente side in World War I when they wrote books such as Fayle's The Great Settlement (1915) and Seton-Watson's The War and Democracy (1915).

In 1917, during World War I, Tomáš Masaryk created the Czechoslovak National Council together with Edvard Beneš and Milan Štefánik (a Slovak astronomer and war hero). Masaryk in the United States (and in United Kingdom and Russia too), Štefánik in France, and Beneš in France and Britain, worked tirelessly to secure Allied recognition. About 1.4 million Czech soldiers fought in World War I, 150,000 of which died.

More than 90,000 Czech and Slovak volunteers formed the Czechoslovak Legions in Russia, France and Italy, where they fought against the Central Powers and later with White Russian forces against Bolshevik troops. At times they controlled much of the Trans-Siberian railway, and they were indirectly involved in the shooting of the Russian Tsar and his family in 1918. Their goal was to win the support of the Allies for the independence of Czechoslovakia. They succeeded on all counts. When secret talks between the Allies and Austrian emperor Charles I (r. 1916–1918) collapsed, the Allies recognized, in the summer of 1918, the Czechoslovak National Council would be the kernel of the future Czechoslovak government.

First Republic (1918–1938)

The Provisional Czechoslovak Government, chaired by Tomáš Garrigue Masaryk, proclaimed the Independence of the Czechoslovak Nation in the Washington Declaration on 18 October 1918. Czechoslovakia was legally created by Law on the Creation of Independent Czechoslovak State (No. 11/1918 Coll.) in Prague on 28 October 1918Stuart Hughes Contemporary Europe: a History Prentice-Hall, 1961 p. 108 in Smetana Hall of the Municipal House, a physical setting strongly associated with nationalist feeling. The Slovaks officially joined the state two days later in the town of Martin. The formation of the state faced immediate opposition from the large German-speaking population in the border regions (Sudetenland/Deutschböhmen), who – appealing to Wilson's Fourteen Points on self-determination – sought to join the new Republic of German-Austria rather than accept inclusion in Czechoslovakia. These attempts ultimately failed due to military occupation by Czechoslovak forces in late 1918/early 1919 and the Allies' decision at the Paris Peace Conference to uphold the historic borders of the Bohemian Crown lands. A temporary constitution was adopted, and Tomáš Masaryk was declared president on 14 November. The Treaty of St. Germain, signed in September 1919, formally recognized the new republic.Niall Ferguson The War of the World Allen Lane, 2006 p. 161 Carpathian Ruthenia was added later by the Treaty of Trianon in June 1920.Stuart Hughes Contemporary Europe: a History Prentice-Hall, 1961, p. 129 There were also various border conflicts between Poland and Czechoslovakia due to the annexation of the Trans-Olza region.

The new state was constituted as the nation-state of the Czech and Slovak peoples and conceived as a representative democracy.. Its 1920 constitution identified the "Czechoslovak nation" as the creator and principal constituent of the Czechoslovak state, established Czech and Slovak as the only official languages, and – by this construction – placed the German population (the second-largest ethnic group at 22.95% in 1921) in a structurally disadvantaged position. Without merging Czechs and Slovaks statistically into one "Czechoslovak nation", the demographic majority vis-à-vis the Germans would have appeared rather weak.

The decision to build the state as the nation-state of the Czech and Slovak peoples inevitably brought ethnic tensions. Chief among them was the intense and confrontational agitation coming from Germans and Hungarians – in particular the German population's push for autonomy or even secession, fueled by opposition to the territorial settlement and by their systematic disadvantages within the new state. Alongside this stood the distinct historical experiences of Czechs and Slovaks, together with their sharply differing religious, cultural, and social traditions – nowhere more evident than in the gulf between the largely secular Czechs and the deeply Catholic Slovaks. The most fundamental lines of division however ran between Czechs and Germans, centred above all on language, national allegiance, and long-standing ethnic rivalry.

Nevertheless, the new republic saw the passage of a number of progressive reforms in areas such as housing, social security, and workers' rights. In 1929, the gross domestic product increased by 52% and industrial production by 41% as compared to 1913. In 1938, Czechoslovakia held 10th place in the world for industrial production.Ekonomika ČSSR v letech padesátých a šedesátých

The operation of the new Czechoslovak government was distinguished by its political stability. Largely responsible for this were the well-organized political parties that emerged as the real centers of power. After 1933, Czechoslovakia remained the only democracy in central and eastern Europe.

Second Republic (1938–1939)

Although Czechoslovakia was the only central European country to remain a parliamentary democracy during the entire period 1918 to 1938,Timothy Garton Ash The Uses of Adversity Granta Books, 1991 p. 60 it faced problems with ethnic minorities such as Hungarians, Poles and Sudeten Germans, which made up the largest part of the country's German minority. The Germans constituted 3 to 3.5 million out of 14 million of the interwar population of CzechoslovakiaPhilip Warner World War II: The Untold Story Coronet, 1990 p. 25 and were largely concentrated in the Bohemian and Moravian border regions known as the Sudetenland.

The rise of Adolf Hitler and Nazi Germany in 1933, the German annexation (Anschluss) of Austria in 1938, the resulting revival of revisionism in Hungary, the agitation for autonomy in Slovakia and the appeasement policy of the Western powers of France and the United Kingdom left Czechoslovakia without effective allies.

After the acquisition of Austria, Czechoslovakia became Hitler's next target.Jozef Garlinski Poland in the Second World War Macmillan, 1985 p. 1Liddell Hart History of the Second World War Pan Book, 1973 p. 6 The German nationalist minority in Czechoslovakia, led by Konrad HenleinEditor Igor Lukes The Munich Crisis, 1938 Frank Cass, 2006 and fervently backed by Hitler, demanded a union of the predominantly German districts of the country with Germany. On 17 September 1938 Hitler ordered the establishment of Sudetendeutsches Freikorps, a paramilitary organization that took over the structure of Ordnersgruppe, an organization of ethnic-Germans in Czechoslovakia that had been dissolved by the Czechoslovak authorities the previous day due to its implication in terrorist activities. The organization was sheltered, trained and equipped by German authorities and conducting cross border terrorist operations into Czechoslovak territory. Relying on the Convention for the Definition of Aggression, Czechoslovak president Edvard BenešPresident Beneš' declaration made on 16 December 1941. and the government-in-exileNote of the Czechoslovak government-in-exile dated 22 February 1944. later regarded 17 September 1938 as the beginning of the undeclared German-Czechoslovak war. This understanding has been assumed also by the contemporary Czech Constitutional court. Stran interpretace "kdy země vede válku", obsažené v čl. I Úmluvy o naturalizaci mezi Československem a Spojenými státy, publikované pod č. 169/1929 Sb. za účelem zjištění, zda je splněna podmínka státního občanství dle restitučních předpisů, Ústavní soud vychází z již v roce 1933 vypracované definice agrese Společnosti národů, která byla převzata do londýnské Úmluvy o agresi (CONVENITION DE DEFINITION DE L'AGRESSION), uzavřené dne 4. 7. 1933 Československem, dle které není třeba válku vyhlašovat (čl. II bod 2) a dle které je třeba za útočníka považovat ten stát, který první poskytne podporu ozbrojeným tlupám, jež se utvoří na jeho území a jež vpadnou na území druhého státu (čl. II bod 5). V souladu s nótou londýnské vlády ze dne 22. 2. 1944, navazující na prohlášení prezidenta republiky ze dne 16. 12. 1941 dle § 64 odst. 1 bod 3 tehdejší Ústavy, a v souladu s citovaným čl. II bod 5 má Ústavní soud za to, že dnem, kdy nastal stav války, a to s Německem, je den 17. 9. 1938, neboť tento den na pokyn Hitlera došlo k utvoření "Sudetoněmeckého svobodného sboru" (Freikorps) z uprchnuvších vůdců Henleinovy strany a několik málo hodin poté už tito vpadli na československé území ozbrojeni německými zbraněmi.

Hitler extorted the cession of the Bohemian, Moravian and Czech Silesian borderlands via the Munich Agreement on 29 September 1938 signed by Germany, Italy, France, and Britain. The Czech population in the annexed lands was forcibly expelled.Jozef Garlinski Poland in the Second World War Macmillan, 1985 p. 2

Finding itself abandoned by the Western powers, the Czechoslovak government agreed to abide by the agreement. Beneš resigned as president on 5 October 1938, fled to London and was succeeded by Emil Hácha. In early November 1938, under the First Vienna Award, Czechoslovakia was forced to cede the mainly Hungarian-populated southern Slovakia (one third of Slovakia) to Hungary. After an ultimatum on 30 September (but without consulting with any other countries), Poland obtained the disputed the Trans-Olza region as a territorial cession shortly after the Munich Agreement, on 2 October. The ultimatum was only sent after Czech request.