251 BC

Millennium:	1st millennium BC
Centuries:	4th century BC – 3rd century BC – 2nd century BC
Decades:	280s BC 270s BC 260s BC – 250s BC – 240s BC 230s BC 220s BC
Years:	254 BC 253 BC 252 BC – 251 BC – 250 BC 249 BC 248 BC

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

**251 BC in other calendars**
Gregorian calendar	251 BC
Ab urbe condita	503
Armenian calendar	N/A
Bahá'í calendar	-2094 – -2093
Bengali calendar	-843
Berber calendar	700
Buddhist calendar	294
Burmese calendar	-888
Byzantine calendar	5258 – 5259
Chinese calendar	[[Sexagenary cycle\|]]年 (2386/2446) — to — [[Sexagenary cycle\|]]年 (2387/2447)
Coptic calendar	-534 – -533
Ethiopian calendar	-258 – -257
Hebrew calendar	3510 – 3511
Hindu calendars
- Bikram Samwat	-194 – -193
- Shaka Samvat	N/A
- Kali Yuga	2851 – 2852
Holocene calendar	9750
Iranian calendar	872 BP – 871 BP
Islamic calendar	899 BH – 898 BH
Japanese calendar
Korean calendar	2083
Thai solar calendar	293

Events

Paseas, the tyrant of the Greek city-state of Sicyon, is assassinated by Nicocles, with the acquiescence of the Macedonian king Antigonus II. Nicocles reigns as tyrant of Sicyon for only four months, during which period he drives into exile eighty of the city's citizens. Then the citadel of Sicyon is surprised in the night by a party of Sicyonian exiles, headed by a young nobleman, Aratus. The palace of the tyrant is set on fire, but Nicocles escapes from the city through a subterranean passage.
Aratus recalls back to Sicyon those exiled by Nicocles. This leads to confusion and division within the city. Fearing that Antigonus II would exploit these divisions to attack the city, Aratus applies for the city to join the Achaean League, a league of a few small Achaean towns in the Peloponnese. Aratus then gains the financial support of the Egyptian king Ptolemy II to enable the Achaean League to defend itself against Macedonia.

The Romans, led by Lucius Caecilius Metellus, attack the Carthaginian held port city of Panormus after taking Kephalodon. After fierce fighting in the Battle of Panormus, the Carthaginians, led by Hasdrubal, are defeated and the city falls.
With Panormus captured, much of western inland Sicily falls with it. The cities of Ieta, Solous, Petra and Tyndaris agree to peace with the Romans in the same year. This defeat marks the end of significant Carthaginian land-based campaigning in Sicily.