How do i find out on what front did my great grandfather fight on?

>>3207472
If you think this is an easy thing to find out, you're dead wrong. I'm a historian, and generally a question like this requires:
-extensive documentation from your grandfather, his training/deployment/service info
-research in the files of the A-H Empire (located in Vienna)

The files in Vienna aren't digitized, so if you don't find your answer on the documents from your grandfather, and you're not willing to go to Vienna, you're fucked.

File: pradjed.png (428KB, 514x604px)

428KB, 514x604px

>>3207489
well fuck then
ill have to ask my mom, since my great grandfather was a croat and i still have a picture of him i am pretty sure that my mom still keeps some of his documents somewhere
him pic related

>>3207499
where did he live, croatia was part of hungary, hungarian army was organised and named based on counties, once you find the unit, its easy to find where he served
unless he was in some special brigade

>>3207681
he lived in Zadar

>>3208055
lived*

>>3207472
I know I probably wont get much out of this either.
But I know a few things about a relative of mine who was in the A-H army.
He was drafted, so he wasn't a officer, he was a Pol so that narrows down his location (I do have the town name somewhere, but I'll need to find it again). He was eventually captured by Russians, and was sent to a prison camp in Siberia. He eventually made it back after he and other prisoners were let out because of the Russian revolution. It took him several years of doing odd jobs in towns to get enough money to keep travailing west. He did make it back to Poland.

Is there anywhere I could start to look for info on a guy like this?