181 BC

Millennium:	1st millennium BC
Centuries:	3rd century BC 2nd century BC 1st century BC
Decades:	200s BC 190s BC 180s BC 170s BC 160s BC
Years:	184 BC 183 BC 182 BC 181 BC 180 BC 179 BC 178 BC

181 BC in various calendars

Gregorian calendar	181 BC CLXXXI BC
Ab urbe condita	573
Ancient Egypt era	XXXIII dynasty, 143
- Pharaoh	Ptolemy V Epiphanes, 23
Ancient Greek era	149th Olympiad, year 4
Assyrian calendar	4570
Balinese saka calendar	N/A
Bengali calendar	−773
Berber calendar	770
Buddhist calendar	364
Burmese calendar	−818
Byzantine calendar	5328–5329
Chinese calendar	己未年 (Earth Goat) 2517 or 2310     — to — 庚申年 (Metal Monkey) 2518 or 2311
Coptic calendar	−464 – −463
Discordian calendar	986
Ethiopian calendar	−188 – −187
Hebrew calendar	3580–3581
Hindu calendars
- Vikram Samvat	−124 – −123
- Shaka Samvat	N/A
- Kali Yuga	2920–2921
Holocene calendar	9820
Iranian calendar	802 BP – 801 BP
Islamic calendar	827 BH – 826 BH
Javanese calendar	N/A
Julian calendar	N/A
Korean calendar	2153
Minguo calendar	2092 before ROC 民前2092年
Nanakshahi calendar	−1648
Seleucid era	131/132 AG
Thai solar calendar	362–363
Tibetan calendar	阴土羊年 (female Earth-Goat) −54 or −435 or −1207     — to — 阳金猴年 (male Iron-Monkey) −53 or −434 or −1206

Year 181 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Cethegus and Tamphilus (or, less frequently, year 573 Ab urbe condita). The denomination 181 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Events

By place

Egypt

• Ptolemy V is poisoned after a reign of 24 years in which the Egyptian kingdom has declined in power and influence and has lost most of its empire outside Egypt other than Cyprus and Cyrenaica. The elder of his two sons, Ptolemy VI Philometor succeeds him, but since he is an infant, he rules under the regency of his mother Cleopatra the Syrian.

Roman Republic

• Rome founds a colony at Aquileia, on the narrow strip of land between the mountains and the lagoons, as a frontier fortress to check the advance of the Illyrians.

Asia Minor

• Pharnaces I of Pontus decides to attack both Eumenes II of Pergamum and Ariarathes IV of Cappadocia and therefore invades Galatia with a large force. Eumenes leads an army to oppose him, however, hostilities are soon suspended following the arrival of Roman deputies, who have been appointed by the Roman Senate to inquire into the matters in dispute. Negotiations take place at Pergamum but are inconclusive, with Pharnaces' demands being rejected by the Romans as unreasonable. As a consequence, the war between Pontus and Pergamum and Cappadocia is renewed.

China

• Empress Lü of the Han dynasty sends an army under Zhou Zao to attack the formerly vassal state of Nanyue in present-day Vietnam and southern China, but the heat and dampness causes many of Zhou's men to fall ill, and he fails to make it across the mountains into enemy territory.
• Nanyue's emperor Zhao Tuo attacks the other vassal kingdoms of Minyue, Western Ou and Luo and secures their submission. He also attacks the state of Changsha.