The siege of Syracuse by the Carthaginians from 311 to 309 BC followed shortly after the Battle of the Himera River in the same year.
In that battle the Carthaginians, under the leadership of Hamilcar the son of Gisco, had defeated the tyrant of Syracuse, Agathocles.
Agathocles had to retreat to Syracuse and lost control over the other Greek cities on Sicily, who went over to the Carthaginian side.
Agathocles suffered a disastrous defeat, a large part of his army was killed or taken prisoner by the Carthaginians.
Hamilcar first besieged Gela, but gave up when he discovered that Agathocles had large supplies and enough soldiers to defend the city.
[1] He lost control over the rest of Sicily, while Carthage had gained superiority in land and naval forces.
[2] Agathocles appointed his brother Antander as the leader of Syracuse and left him an adequate garrison to defend the city.
[3] Because he needed money for his campaign, he took the property of orphans, borrowed from merchants, took dedications from temples and the jewels of the women.
[3] The Carthaginians were blockading the harbor of Syracuse with a fleet of triremes which greatly outnumbered the sixty ships of Agathocles had manned.
[4] The Carthaginians at first thought Agathocles intended to rescue the grain ships, so they turned to face him in a battle formation.
The Greek fleet was almost overtaken by the Carthaginians, but was saved when night set in, making further pursuit impossible.
[6] When Agathocles had left the landing site, the Carthaginians took the bronze beaks of the burnt Greek ships to Carthage.
They presented the beaks as evidence to convince the Syracusans that the army of Agathocles had been destroyed and to ask for their surrender.
Many inhabitants believed the story and mourned their lost relatives, but the magistrates were in doubt and turned away the Carthaginian messengers.
Hamilcar, thinking that the morale of the Syracusans was broken and that they lacked men to defend the city, prepared to assault the walls of Syracuse.
Because he had not been able to take Syracuse that day, he decided to send 5000 soldiers to the aid of Carthage in response to the request of the messengers.
Hamilcar had by now occupied the area around the Olympieum (which was situated south of the city on the shore of the Great Harbour, near the mouth of the Anapus River) and prepared a second attack on the walls.
Without Hamilcar to hold the army together, the Greek allies separated from the Carthaginians and elected Deinocrates as their general.
[16] The city of Acragas, which was among the Greek allies of Carthage, now thought the time was ripe to take the leadership of Sicily for itself.
Under the leadership of their general Xenodicus they proceeded to liberate the cities Gela, Enna and Erbessus from Carthaginian control and restore their autonomy.