Before WW1 Czechoslovakia was a part of Austro-Hungarian Empire.
During the war Czechs living outside the Austro-Hungarian Empire or those who
had crossed the border, joined the allied war effort - in the hope of the establishment
of a Czecho-Slovak state as a sovereign and democratic country, consisting of
historic Czech lands and those parts of Upper Hungary inhabited by the Slovaks.
The Austrian army had conscripted large numbers of Czechs, most of whom shared the dream of their compatriots of an independent state. When captured by the allies, many of them volunteered to fight the Austrians and Germans. Czech battalions were established in France, Italy and Russia, although in Russia the inclusion of ‘prisoners-of-war’ was not approved until after the abdication of the Tsar. As their numbers grew, they were formed into legions but in Russia, with the collapse of the Provisional Government and the Bolshevik take-over of power, the Czech Legion was never deployed. The new Soviet government quickly made peace with Germany, leaving the Legion in Russia isolated.
At the same time, the allies were being lobbied intensely by Czechs in exile and there were strong signs that they would be rewarded by the creation of a Czech and Slovak state at the end of the war. The Czech leader, Masaryk (later the first president of Czechoslovakia), was in Russia in 1917 during the chaos of the Revolution and resolved, after consultation with the allies who were still engaged in bitter fighting on the Western Front, to transfer the Russian Legion to France and to join in the war effort there.
The Legion at this point was in the Ukraine. The war barred any route westwards to France and it was decided that the Russian Legion should make its way via Vladivostok and ship to France. The only route was by the vitally strategic Trans-Siberian Railway. The Legion, now numbering between 70,000 and 100,000 men with all the equipment an army of that size carries, set off to the East in the Spring of 1918 but ran into one obstacle after another. Local Bolsheviks, in particular, for whom the Trans-Siberian was also a vital artery, regularly confronted Czech troops and the Legion’s commanders decided that their only recourse was to seize the Railway and fight their way out.
The Czech army drifted into an alliance with the White Russians in the area, who were fighting the Bolsheviks, and Czech troops who had reached Vladivostok even retraced their steps to help protect the Railway and take the battle to the Bolsheviks. Legion became the backbone of resistance to the Soviets. It even succeeded in reaching close to Ekaterinburg, where the ex-Tsar was being kept. Fear of his falling into the hands of the Legion and being ultimately restored as ruler of Russia prompted Lenin to approve of the Tsar and his family's execution in July 1918.
When the war in Europe came to an end in November 1918, the Czech Army was still in Siberia. Back home, in the newly created state of Czechoslovakia, views varied between getting them home quickly and having them fight an all-out war against Bolshevism. The commanders on the ground decided to withdraw their support for the White Russian cause and to marshal their forces along the line of the Railway, protecting their position until allied ships could reach Vladivostok and get them home.
The White Russians were defeated in the Summer of 1919 but the Czechs continued to hold the Railway until their eventual withdrawal and departure from Vladivostok in April 1920 and it was in this latter period that the postage stamps were issued:
The 25 kopek stamps depicts a church in Irkutsk, nearly half-way
between Omsk and Vladivostok.
The 50 kopek stamp depicts an armoured train named Orlik, a significant factor in the Czechs maintaining control of the line.
And the One Rouble stamp shows a sentry, large numbers of whom would have been required on a railway of this immense length.