278 BC

Millennium:	1st millennium BC
Centuries:	4th century BC – 3rd century BC – 2nd century BC
Decades:	300s BC 290s BC 280s BC – 270s BC – 260s BC 250s BC 240s BC
Years:	281 BC 280 BC 279 BC – 278 BC – 277 BC 276 BC 275 BC

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

**278 BC in other calendars**
Gregorian calendar	278 BC
Ab urbe condita	476
Armenian calendar	N/A
Bahá'í calendar	-2121 – -2120
Bengali calendar	-870
Berber calendar	673
Buddhist calendar	267
Burmese calendar	-915
Byzantine calendar	5231 – 5232
Chinese calendar	[[Sexagenary cycle\|]]年 (2359/2419) — to — [[Sexagenary cycle\|]]年 (2360/2420)
Coptic calendar	-561 – -560
Ethiopian calendar	-285 – -284
Hebrew calendar	3483 – 3484
Hindu calendars
- Bikram Samwat	-221 – -220
- Shaka Samvat	N/A
- Kali Yuga	2824 – 2825
Holocene calendar	9723
Iranian calendar	899 BP – 898 BP
Islamic calendar	927 BH – 926 BH
Japanese calendar
Korean calendar	2056
Thai solar calendar	266

Events

After their defeats in Greece, the Gauls move into Asia Minor. The Seleucid king Antiochus wins a major battle over the Gauls leading to his being given the title of Soter (Greek for "saviour"). The Gauls settle down to become the "Galatians" and are paid 2,000 talents annually by the Seleucid kings to keep the peace.
Antigonus concludes a peace with Antiochus who surrenders his claim to Macedonia. Thereafter Antigonus II's foreign policy is marked by friendship with the Seleucids.
Nicomedes I becomes the first ruler of Bithynia to assume the title of king. He founds the city of Nicomedia, which soon rises to great prosperity.

The Carthaginians seize an opportunity to interfere in a quarrel between Syracuse and Agrigentum and besiege Syracuse. The Syracusans ask for help from Pyrrhus and Pyrrhus transfers his army there.
On his arrival in Sicily, Pyrrhus' forces win battles against the Carthaginians across Sicily. Pyrrhus conquers almost all of Sicily except for Lilybaeum (Marsala).
Pyrrhus is proclaimed king of Sicily. He plans for his son Helenus to inherit the kingdom of Sicily and his other son Alexander to inherit Italy.

Chu's heartland in the modern Hubei province is overrun by the powerful state of Qin from the west under Bai Qi's leadership. The Chu government moves to the east in various temporary capitals until settling in Shouchun in 241 BC.
Qu Yuan writes the poem "Lament for Ying" after the fall of the capital of Chu.

Polyaenus of Lampsacus, Greek mathematician and philosopher and friend of Epicurus (b. c. 340 BC)
Qu Yuan, Chinese poet from southern Chu who lived during the Warring States Period. His works are mostly found in an anthology of poetry known as Chu Ci (b. c. 340 BC)