171 BCE

Thanks to the efforts of Eumenes II of Pergamum while in Rome, the Romans declare war on Macedonia and send troops to Thessaly, thus beginning the Third Macedonian War. In the resulting Battle of Callicinus the Macedonians, led by their king, Perseus, are victorious over a Roman force led by consul Publius Licinius Crassus. Mithradates I succeeds his brother Phraates I as king of Parthia. The first Roman colony outside Italy is founded at Carteia in southern Hispania after Iberian-born descendants of Roman soldiers appear before the Roman Senate to request a town to live in and are given Carteia, which is named Colonia Libertinorum Carteia.

Geopolitics & Diplomacy

Mithradates I succeeds his brother Phraates I as king of Parthia.source

Conflict & Security

Thanks to the efforts of Eumenes II of Pergamum while in Rome, the Romans declare war on Macedonia and send troops to Thessaly, thus beginning the Third Macedonian War. In the resulting Battle of Callicinus the Macedonians, led by their king, Perseus, are victorious over a Roman force led by consul Publius Licinius Crassus.source
Epirus joins Macedonia in the latter's fight against Rome. However, the leagues of southern Greece remain neutral.source
Boiotian League dissolved by the Romans.source

Exploration & Expansion

The first Roman colony outside Italy is founded at Carteia in southern Hispania after Iberian-born descendants of Roman soldiers appear before the Roman Senate to request a town to live in and are given Carteia, which is named Colonia Libertinorum Carteia.source

Religion & Belief

Lucius Postumius Albinus is sent by Rome as an ambassador to King Masinissa of Numidia, and to the Carthaginians in order to raise troops for the war against Perseus of Macedonia.source

Deaths

Phraates I, King of Parthia, who has ruled the country since 176 BCsource