PROVINCIA ILLYRIAE
The seizure of Illyria by the Romans was a gradual affair, and one framed within the issue of Rome’s long term strategic and security needs versus the continuous rebellious spirit of the local tribes.
After the Third Illyrian War (168 BC) was won and Illyrian piracy finally quelled, Rome proceeded to formally annex most of the lands belonging to this province. Nonetheless, despite its strategic importance as a defensive flank for the Italian lands, and to prevent piracy, the land was quite poor, scarcely inhabited and hard to travel through. Many of the local native tribes were restless and independent, and would take effectively two centuries of quelled rebellions to be subjugated into the nascent Roman empire.
Many of the Illyrian cities and tribes which had been native to the region and sided with Rome were then subject to the Republic, but were practically independent or had a great local autonomy and paid only half the taxes they paid to their previous native Illyrian overlords. Roman settlement, however, is recorded from this period and begins in earnest at the foundation of the city of Aquileia, in 181 BC, with the expulsion and exodus of the local tribes. This initial Roman settlement comprised 3000 families, with another 1500 families of Roman origin also coming by in 169 BC.
Illyria, however, was not a formal province in the sense that other provinces at the same time during the late Republic were or were about to become (such as Gallia Narbonnensis or Hispania Citerior), but rather a territory under the formal occupation of the Roman Senate, and as such ruled not by a provincial governor but by a military dictatorship strictly under Roman control. It thus remained a wild, remote place, with large uninhabited areas that were difficult to transverse – while the local peoples themselves rose in rebellion again during the 1st Century BC. The economy was also very poor compared to other provinces, while Romanization and full control only ever achieved significant status with the end of the Republic, the quelling of the last local rebellions (where most tribes would side either with Pompey or Caesar during the Civil War), and the installation of a formal provincial government with the organization of the province of Illyricum by Emperor Augustus in 27 B.C, who campaigned in the region and defeated the local tribes that had rebelled against the Roman yoke during times of instability.
Later on, after the EB2 time frame, Illyria would become consistently and effectively Romanized, becoming a valuable source for highly prized legionary officers. Some later Roman emperors would also come from Illyricum, like Probus or Diocletian, who ruled Rome during the crisis of the 3rd century AD.