Salvete amici!
Χαιρετε φιλοι!

Wikingus,
Being interested in the history of the Illyrians during the Roman times ,I suggest that you read the book of professor John Wilkes-the Illyrians.It is an excellent book where you can grasp the 'atmosphere' for your novel.There is also some great work done by archeologists like Moksy and Alfoldy.

The Pannonians were included in the group of people called illyrians by the Greeks(however there were numerous tribes extending from what is now Albania to Slovenia and Hungary and they did not had some kind of political union).
They came into contact with the Romans since around 200 B.C but they were subdued to Rome at the time of Augustus and Tiberius(referring to the Panonians).There were many legions stationed in their regions(one of them was LegioVII claudia stationed in Scupi which was a roman colony) and many Illyrians followed an army carreer,either at first as auxiliaries and later their offsprings as legionarries.
The culture of the provinces was mainly provincial Roman,most of the Illyrians spoke Latin,they worshipped Silvanus,a Roman deity, and Diana(it fits to their warlike nature).Most of the people who did not live in towns and cities,were shepherds and farmers.Many worked in the numerous mines that were in the region.But the majority of the Romano-Illyrians or Illyrio-romans were professional soldiers.After the reign of Severus,the praetorians in Rome were Pannonians or Illyrians(10.000 men).
There were also many emperors being born in Illyrian provinces or being of Ilyrian origin like Constantine,Julianus and many many other.