Year 229 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Albinus and Centumalus (or, less frequently, year 525 Ab urbe condita). The denomination 229 BC for this year has been used since the early medieval period, when the Anno Dominicalendar era became the prevalent method in Europe for naming years.
Concerned at Rome's expansion, Antigonus III pursues a policy of befriending the Illyrians, even though the Greeks in the region support Rome in quelling the Illyrian pirates.
The involvement of Rome in Illyria leads to the establishment of friendly relations between Rome and the enemies of Macedonia: the Aetolian League and Achaean League, which approve the suppression of Illyrian piracy.