Mediolanum (modern Milan), stronghold of the Gallic tribe of the Insubres (led by Viridomarus), falls to Roman legions in Lombardy (led by consul, Marcus Claudius Marcellus), in the Battle of Clastidium. Marcus Claudius Marcellus personally slays the chief, Viridomarus. This victory removes the Gallic threat to Rome. Marcellus wins the spolia opima ("spoils of honour"; the arms taken by a general who kills an enemy chief in single combat) for the third and last time in Roman history.
Almost all of Greece falls under Macedonian suzerainty after Antigonus III re-establishes the Hellenic Alliance as a confederacy of leagues, with himself as president.
Seleucid Empire
The Seleucid forces under their general Achaeus succeed in winning back from Pergamum all the Seleucid domains in Anatolia lost six years earlier.