View source for 425 BC

=== By place ===
==== Persian Empire ====
* [[Artaxerxes I]], [[Achaemenid]] king of [[Persia]], is succeeded by his son [[Xerxes II]].   

==== Greece ====
* [[Aristophanes]] produces the comedy, [[Archanians]].<ref>{{cite web | url=https://www.britannica.com/biography/Aristophanes | access-date=February 24, 2024 | title=Aristophanes | series=Encyclopædia Britannica | date=January 19, 2024 | first1=Maurice | last1=Platnauer | first2=Oliver | last2=Taplin}}</ref>
* [[Demosthenes (general)|Demosthenes]] captures and fortifies the port of [[Pylos]] in the [[Peloponnesus]], giving [[Athens]] a strong base close to [[Sparta]]. Meanwhile, a Spartan army, commanded by [[Brasidas]], lands on the nearby island of [[Sphacteria]], but is repulsed by the Athenians. An Athenian fleet summoned by Demosthenes bottles up the Spartan navy in [[Pylos|Navarino]] Bay.
* [[Cleon]] joins Demosthenes in the invasion by Athenian troops of Sphacteria. The resulting [[Battle of Pylos]] results in an Athenian victory leading to the surrender of many of the Spartan troops. Pylos remains in Athenian hands, and is used as a base for raids into Spartan territory and as a refuge for fleeing Spartan [[helots]].
* Following the failure of peace negotiations between Athens and Sparta, a number of Spartans stranded on the island of Sphacteria after the Battle of Pylos are attacked by an Athenian force under Cleon and Demosthenes. The resulting [[Battle of Sphacteria]] leads to a further victory by the Athenians over the Spartans. The Spartans sue for peace, but the Athenian leader Cleon persuades Athens to refuse.

==== China ====
* [[Zhou wei lie wang]] becomes king of the [[Zhou dynasty]] of [[China]].