Nicomedes' second wife Etazeta becomes ruler on behalf of her infant sons after his death in 255 BCE.

The grown-up Ziaelas, son of Nicomedes and Ditizele and thus excluded from the throne, had previously fled to Armenia and taken refuge at the court of King Arsames I in Sophene.

On his father's death, he immediately endeavors to regain his rights by force and returns, aided by some Galatians.

Although Etazeta is supported by neighboring cities and Antigonus II Gonatas, Ziaelas rapidly conquers first part, then all of Bithynia, forcing Etazeta and her sons to escape to Antigonus' court in Macedonia about 254 BCE.

The Romans are able to rally after the African debacle, and quickly resume the offensive.

Along with constructing a new fleet of one hundred and forty ships, Rome returns to the strategy of taking the Carthaginian cities in Sicily one by one.

Attacks begin with naval assaults on Lilybaeum, the center of Carthaginian power on Sicily, and a raid on Africa.

Ptolemy brings the war with the Seleucid Empire to an end in 253 by marrying his daughter, Berenice—who he provide with a huge dowry—to his foe Antiochus II.

Under the agreement, Berenice supplants Antiochus' first wife, Laodice, whose children she persuades him to bar from the succession to the throne in favor of her own prospective offspring.

Gonatus' position in Greece is now shaken by a number of reversals.

His nephew and viceroy Alexander revolts in Corinth with Ptolemy's help in 253 and declares himself an independent monarch.

Gonatus loses Corinth and …

…Chalcis, the two bases from which he dominates southern Greece.

Moreover, as the Aetolians have occupied Thermopylae, Gonatus is cut off from Athens and the Peloponnese.

Rome’s efforts against Carthage end in failure.

The Romans retreat from Lilybaeum, and the African force is caught in another storm and destroyed.

The Romans make great progress in the north, however.

The city of Thermae is captured in 252 BCE, enabling another advance on the port city of Panormus.

Aratus, a brilliant twenty-year-old guerrilla fighter with a hearty loathing for tyrants and Macedon alike, frees Sicyon from a tyranny in 251 and, after establishing a democracy, brings it into the Achaean League for defense against Macedonia.

The Romans attack Panormus after taking Kephalodon in 251 BCE.

After fierce fighting, the Carthaginians are defeated and the city falls.

With Panormus captured, much of western inland Sicily falls with it.

The cities of Ietas, Solous, Petra, and Tyndaris agree to peace with the Romans this same year.