Since no one answered I'll tell you what I know and give you a few things you can look up.

So, from a cemetery in Prague I know that they fought (and died) in Italy, places like Slovenia and Croatia, anywhere the Austrians fought.

Many also didn't think it right they should be fighting their Slavic brothers under the Austrians and went over the Russian side and fought the Austrians. Many, actually did that. Also to France and England. French, Russian, but also other armies had hundreds or thousands of Czechs and Slovaks fighting for them against the Germans and Austrians.

I co-host a show about Czech history called http://bohemican.com and we did a few shows that touch on this:

The Czech foreign legion, they have an awesome tale of going all the way around the world after WWI because they were on the wrong side of the Red Army in Russia during the revolution... so they went the long way home. Through Russian to Japan and the US and Paris. Some circled around India. They had some tzarist gold at one point, which makes for great legends. They had an armored train (pics elsewhere if you're interested)

Anyway, we did a few WWI shows because it's the centennial, so go have a listen.

If you have any follow up questions, feel free. I think I answered a similar question before, so I can try and find my answer.

By sister-in-law got a book from her boyfriend The Czech and Slovak Legion in Siberia, 1917-1922. We teased him but (after a year or two) he actually told us what it was about and it sounded pretty interesting.

There was a sizeable number of Czechs and Slovaks as well as Ruthenians, the future citizens of Czechoslovakia, if you will, in the Austro-Hungarian armed forces during the Great War. However, you are correct in that the legacy of the Legion has massively overshadowed this part of Czech history. Although perhaps this is understandable to an extent, given the impact of the Legion – and the wider implications of anti-Austrian and pro-independence sentiment in general – on the fledgling state.

Czechs are estimated to have comprised between around twelve percent of the imperial armed forces, a number roughly corresponding to their percentage in the population of Austria-Hungary as a whole. This means that upwards of about a million Czechs had served, with some historians suggesting a number as high as one and a half million soldiers. At the outbreak of the war the aim was to have individual regiments filled with a single or a small number of nationalities, but as the conflict dragged on, these attempts gave way to the practical and logistic side of things.

Out of the above number, some 138 thousand have died according to interwar research by Austrian officer and statistician Wilhelm Winkler (compare to just over five thousands Legionnaires). This number is by no means one hundred percent precise, as it was arrived at by checking the manpower losses from districts and regions of the country with an "over 80 % Czech population". The majority of these casualties would, quite unsurprisingly, come from the eastern front, with a smaller number of losses recorded in Italy.

An interesting sidenote is that the Czech lands' being comparably well developed also played a part in the make up of the Austro-Hungarian army. The Czechs were well represented in specialized positions in both the navy and aviation branches, apparently making up about a fourth of the ground crew personnel, for example, owing to the industrialized background of their homeland. However, they were not necessarily limited to technical posts – Václav Voseček, the first commander of the Seeflugwesen, the navy aviation arm, and Jindřich Kostrba, one of the first Austro-Hungarian flying aces, being good examples.

That being said, the Czechs only comprised between five and eight percent of the army officer corps, which should come as no surprise in an Austrian dominated monarchy. Furthermore, both during the war and following its end the Czechs have developed a reputation of unreliability, a tendency to desert or general lack of loyalty, with tales of whole regiments deserting en masse. Maybe you are familiar with Jaroslav Hašek's novel The Good Soldier Švejk, which is partly also guilty of promoting this phenomenon.

Certainly, the above does have some roots in historical fact, but is generally quite overblown. The national independence movement, the actions of Czechs in exile, the founding of the Legions were all real, tangible factors that could undermine trust towards Czechs on the part of Austria-Hungary. Incidentally, one of the sparks of this sentiment was the battle of Zborov, the first major deployment of the Legionnaires in Russia. A larger Austro-Hungarian force including two Czech regiments was soundly defeated by the Legion, raising suspicion towards Czech troops and their loyalties.

However, while desertion of sometimes whole units did happen, ultimately the vast majority of Czechs stayed in the service of the Austro-Hungarian army – compare the million or so Czechs with the 90 thousand in the Legions across three fronts. Another often overlooked fact is that Czechs often joined the Legions not as outright deserters but after being captured by the Russians, and that a large percentage of desertions occured betwen 1917 and 1918 after Brest-Litovsk when disillusioned troops or prisoners of war were returning from the east and went away without leave.

Speaking of Russians, the reputation the Czechs had developed was also a product of being deployed to that particular theater of war. The idea of panslavism was still strong and the possibility of Russia helping Czech independence seemed realistic enough to influence the soldiers on the frontlines with Russia, as opposed to the war in Italy, where the issue of loyalty was nowhere near as prominent.

Yet in the end, it was the founding of Czechoslovakia and the efforts of the Legions that became the much more important historical narrative. The lack of spotlight did not somehow make over a million soldiers and their legacy disappear completely – a good example being the post-war officer corps, a third of which were former imperial army officers – but it is true that the Czechoslovak Legions or The Good Soldier Švejk are what has constituted popular history of the Czechs in the Great War for some time now, despite the many monuments to the fallen of the Austro-Hungarian army that can still be found across the Czech Republic today.