Episode I: An Ignored War
Classical sources suggest that the Romans fought a brief war during 221-220 B.C.E. against the Istrians. According to these accounts, the war was caused by piratical assaults from the Istri against the Roman ships in northern Adriatic. Also, it is suggested that the Istri may have been collaborating as allies with Demetrius of Pharus against the interests of the Roman Republic. This short campaign against the Istrians has been treated by modern sources as part of the Roman expansion into Cisalpine Gaul as well as the securing of the frontiers just before the outbreak of the Second Punic War. Overall, the Roman engagement in this part of the Adriatic reflects the increased interest of the Republic on the matters of the eastern regions. Although it contributes to the more in depth understanding of the early Roman expansion, the Istrian War has received little attention from modern scholars in part because the evidence related to it are limited.
According to Roman accounts, the war against the Istrians in 221 was caused by Istrian assaults on Roman grain ships. The consuls of that year Marcus Minucius Rufus and Publius Cornelius Scipio led the campaign against the Istrians. The consuls used the naval base at Ancona to sail towards the Istrian peninsula. Both these Roman commanders were already highly valued as nobles but the career of Minucius saw a significant rise after 221 apparently due to his distinguished military leadership in the Istrian campaign. (Thus, in 220 Minucius was appointed dictator magister equitum and it was potentially voted dictator again in 217 after the famous loss at Trasimene). Even though the Romans won the war against the Istrians in general, Orosius implies that the Republican army suffered serious losses during this campaign.
Episode II: The Istrian-Illyrian connections
There are several reasons why the Istrian War has been linked with the Second Illyrian War. These reasons include: the fact that the campaign against the Istrians was concluded just one year before the outbreak of the Second Illyrian War; the mentioning of Demetrius of Pharus (the leader of the Illyrians during the Second Illyrian War) as an ally of the Istrians in the events preceding the Roman campaign in Istria; the listing of the Istri as an Illyrian tribe by Appian thus suggesting a cultural link between the Istri and the Illyrians under the leadership of Demetrius; the fact that both these anti-Roman entities were positioned northeast of the Adriatic and not far from each other.
Dell (1970) suggests that Appian has confused the events related with the Istrian War (221-220) with the events related to the Second Illyrian War just one year later (219). Therefore, the establishment of an alliance between the Istri and Demetrius against Rome is highly debatable. The doubts over the existence of such alliance should not be used to disregard the occurrence of the Istrian War. Classical sources offer enough insights to conclude that this war did actually happen and allowed the Romans to expand their possessions. Dell offers this rare interpretation of the war:
“ It is clear that the Scipio-Minucius campaign (221) was waged on land, taking some Istrian towns by storm and other by their outright surrender. Further, we are told that the consuls for the succeeding year (220), C. Lutatius Catulus and L. Veturius Philo, were occupied with a campaign, which reached as far as the Alps. This seems to have been a campaign to confirm the gains of the previous year by winning over the neighboring peoples without actually conquering them. This explains why the Romans were not ready to deal with Demetrius until 219; for their attention was still fixed on the north.”
Appian. Historia Romana. Illyrike.
Dell, H.J. (1970). Demetrius of Pharos and the Istrian War. Historia: Zeitschrift für Alte Gershichte, 19, 30-38.