181 BC

Millennium:	1st millennium BC
Centuries:	3rd century BC – 2nd century BC – 1st century BC
Decades:	210s BC 200s BC 190s BC – 180s BC – 170s BC 160s BC 150s BC
Years:	184 BC 183 BC 182 BC – 181 BC – 180 BC 179 BC 178 BC

181 BC by topic
Politics
State leaders – Sovereign states
Birth and death categories
Births – Deaths
Establishments and disestablishments categories
Establishments – Disestablishments

**181 BC in other calendars**
Gregorian calendar	181 BC
Ab urbe condita	573
Armenian calendar	N/A
Bahá'í calendar	-2024 – -2023
Bengali calendar	-773
Berber calendar	770
Buddhist calendar	364
Burmese calendar	-818
Byzantine calendar	5328 – 5329
Chinese calendar	[[Sexagenary cycle\|]]年 (2456/2516) — to — [[Sexagenary cycle\|]]年 (2457/2517)
Coptic calendar	-464 – -463
Ethiopian calendar	-188 – -187
Hebrew calendar	3580 – 3581
Hindu calendars
- Bikram Samwat	-124 – -123
- Shaka Samvat	N/A
- Kali Yuga	2921 – 2922
Holocene calendar	9820
Iranian calendar	802 BP – 801 BP
Islamic calendar	827 BH – 826 BH
Japanese calendar
Korean calendar	2153
Thai solar calendar	363

Events

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.

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.

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.

Ptolemy V Epiphanes, Ptolemaic dynasty ruler of Egypt who has reigned from 204 BC