Year 150 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Flamininus and Balbus (or, less frequently, year 604 Ab urbe condita). The denomination 150 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.
The Roman Senate shows displeasure with Carthage's decision to wage war against its neighbour without Roman consent, and tells Carthage that in order to avoid a war it has to "satisfy the Roman People". The Roman censor, Cato the Elder, urges the destruction of Carthage and the Roman Senate orders the gathering of an army.
Nicomedes, the son of king Prusias II of Bithynia, who has been sent to Rome to argue for smaller reparations arising from his father's unsuccessful war against Pergamum, gains the support of the Roman Senate to the point where Prusias sends an emissary with secret orders to assassinate Nicomedes. However, the emissary reveals the plot to Nicomedes and persuades him to rebel against his father.
The Romans, led by praetorServius Sulpicius Galba, defeat the Lusitanians in a major battle in Hispania. He then breaks his promise to the defeated Lusitanian rebels by instituting a massacre of 9,000 of their number during the peace talks. Later 20,000 more Lusitanians are sold as slaves in Gaul.