View source for 304 BC

== Events ==
<onlyinclude>

=== By place ===

==== Greece ====
* [[Demetrius Poliorcetes|Demetrius]] shows ingenuity in devising a new siege engine: a wheeled siege tower named [[Helepolis]] (or "Taker of Cities"), which stands 40 meters tall and 20 meters wide and weighs 180 tons.<ref name="Diodorus91">{{cite book|last=Siculus|first=Diodorus|title=Library|url=https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Diodorus_Siculus/20E*.html#91|volume=XX|chapter=91}}</ref> 
* The [[Siege of Rhodes (305–304 BC)|Siege of Rhodes ]] ends after a year. 
*[[Demetrius Poliorcetes]] and the Rhodians come to a truce, with the agreement that the city should be autonomous, should keep its own revenue and that the Rhodians should be allies of Antigonus unless he is at war with [[Ptolemy I Soter|Ptolemy]].<ref name="Diodorus99">{{cite book|last=Siculus|first=Diodorus|title=Library|url=https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Diodorus_Siculus/20E*.html#99|volume=XX|chapter=99}}</ref> 
* [[Antigonus I Monophthalmus|Antigonus]] then concludes a peace treaty and an alliance with the island state, guaranteeing it autonomy and neutrality in his conflicts with [[Ptolemy I Soter|Ptolemy]].<ref Name="Dupuy54">{{cite book |title=The Encyclopedia of Military History |last=Dupuy |first=R. Ernest |last2=Dupuy |first2=Trevor N. |year=1986 |publisher=Harper & Row |location=New York |isbn=0-06-181235-8 |page=54 }}</ref><ref name="Diodorus99">{{cite book|last=Siculus|first=Diodorus|title=Library|url=https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Diodorus_Siculus/20E*.html#99|volume=XX|chapter=99}}</ref> 
* [[Cassander]] invades [[Attica]] and besieges [[Athens]]. He captures the island of [[Salamis Island|Salamis]] off the coast of Athens.
*[[Demetrius Poliorcetes]] invades mainland Greece for Asia-Minor, drives Cassander out of central Greece and liberates Athens. In return, the Athenians bestow on him a new religious honour, synnaos (meaning "having the same temple") of the temple of the goddess [[Athena]].

==== Roman Republic ====
* The [[second Samnite war]] formally ends with a peace agreement in which the [[Samnites]] obtain peace on terms that are severe but not as crushing as those agreed by the [[Roman Republic|Romans]] with the [[Etruscans]] four years earlier. Under the peace, Rome gains no territory, but the Samnites renounce their hegemony over [[Campania]]. Rome is also successful in ending the revolts amongst the tribes surrounding Roman territory.<ref Name="Dupuy59">{{cite book |title=The Encyclopedia of Military History |last=Dupuy |first=R. Ernest |last2=Dupuy |first2=Trevor N. |year=1986 |publisher=Harper & Row |location=New York |isbn=0-06-181235-8 |page=59 }}</ref>

==== Sicily ====
* The tyrant [[Agathocles of Syracuse]] takes on the title of King of [[Sicily]]. He extends his influence into southern [[Italy]] and the [[Adriatic]].

==== India ====
* The [[Maurya]]n emperor [[Chandragupta Maurya|Chandragupta]] defeats [[Seleucus I Nicator]] as he tries to invade [[India]].</onlyinclude>