The world in 181 BC — what happened that year

7 events the sources record for this year, grouped by region.

What happened

Nanyue invaded Changsha; Marquis Longlü Zao led troops and attacked. (Book of Han (Hanshu), Imperial Annals 漢書卷003 高后七年九月)
Empress Lü imprisoned King You of Zhao in a lodging in Chang'an and starved him to death. (Records of the Grand Historian (Shiji), Annals 史記卷009 呂太后本紀)

Philip crossed the wasteland between Maedica and Haemus and reached the foot of the mountains after seven days (Livy, History of Rome (Ab Urbe Condita) 40.22)
The Etruscan colony of Gravisca is founded on land taken from the Tarquinienses (Livy, History of Rome (Ab Urbe Condita) 40.29)
When Flaccus plundered Celtiberia and stormed fortresses, most of the tribes surrendered (Livy, History of Rome (Ab Urbe Condita) 40.33)
As consul, Aemilius campaigns against the Ligurians of the Alps (Plutarch's Parallel Lives Plut. Aemilius Paulus 6.1)
In winter Pharnaces invades Cappadocia (Polybius, Histories 24.8)