Centuries:	4th century BC - 3rd century BC - 2nd century BC
Decades:	290s BC  280s BC  270s BC - 260s BC - 250s BC  240s BC  230s BC
Years:	266 BC 265 BC 264 BC - 263 BC - 262 BC 261 BC 260 BC

263 BC by topic

Politics

State leaders - Sovereign states

Birth and death categories

Births - Deaths

Establishments and disestablishments categories

Establishments - Disestablishments v • d • e

263 BC in other calendars

Gregorian calendar	263 BC
Ab urbe condita	491
Armenian calendar	N/A
Bahá'í calendar	-2106 – -2105
Berber calendar	688
Buddhist calendar	282
Burmese calendar	-900
Byzantine calendar	5246 – 5247
Chinese calendar	[[Sexagenary cycle|]]年 (2374/2434) — to — [[Sexagenary cycle|]]年 (2375/2435)
Coptic calendar	-546 – -545
Ethiopian calendar	-270 – -269
Hebrew calendar	3498 – 3499
Hindu calendars
- Vikram Samvat	-207 – -206
- Shaka Samvat	N/A
- Kali Yuga	2839 – 2840
Holocene calendar	9738
Iranian calendar	884 BP – 883 BP
Islamic calendar	911 BH – 910 BH
Japanese calendar
Korean calendar	2071
Thai solar calendar	281
v • d • e

Events

By place

Roman Republic

• The Romans under the consul Manius Valerius Messalla secure the alliance of Hiero II of Syracuse. The treaty with Rome restricts Hieron II's kingdom to southeast Sicily and the eastern coast of Sicily as far as Tauromenium. From this date until his death, Hieron II remains loyal to the Romans.

Greece

• Alexander II of Epirus attacks and conquers the greater part of Macedonia. However, he is then driven out of both Macedonia and Epirus by Demetrius II, the son of King Antigonus II Gonatas of Macedonia.
• The Athenians and Spartans, worn down by several years of war and the devastation of their lands, make peace with Antigonus II of Macedonia who thus retains his hold on Greece.
• Cleanthes succeeds Zeno of Citium in his Stoic School in Athens.

Asia Minor

• Eumenes I succeeds his uncle Philetaerus to the throne of Pergamum. As Philetaerus was a eunuch, he adopted his nephew Eumenes (the son of Philetaerus' brother also named Eumenes) as his successor.

Births

• Antigonus III Doson, king of Macedonia from 229 to 221 BC

Deaths

• Philetaerus, founder (reigned from 282 BC) of the Attalid dynasty, a line of rulers of a powerful kingdom of Pergamum, in northwest Asia Minor (b. c. 343 BC)