Editing 3rd century BC (section)

===[[240s BC]]===
*[[246 BC]]: The death of [[Antiochus II]] sparks the [[Third Syrian War]]; [[Ptolemy III]] conquers Syria and Babylon from the Seleucids, but loses the [[Nesiotic League]] to [[Antigonus II]]
*[[243 BC]]: Surprise attack on the [[Macedon]]ian garrison at [[Corinth]]. Expansion of the Achaean League.
*[[241 BC]]: [[First Punic War]] ends in Carthaginian defeat. Rome demands large reparations, and annexes [[Sicily]] and [[Corsica]].
*[[240 BC]]: On May 15, Chinese mathematicians observed and recorded the passage of the [[Halley's Comet]].
[[File:Terrakottaarmén.jpg|thumb|right|The [[History of China|Chinese]] [[Terracotta Army]] of [[Qin Shi Huang]]'s tomb at [[Xi'an]], [[Shaanxi]], China]]