Upon taking the Seleucid throne in 223 BCE, Antiochus III (241–187 BCE) had set himself the task of restoring the lost imperial possessions of Seleucus I Nicator, which had extended from the Greco-Bactrian Kingdom to India in the east, the Hellespont in the north, and Syria in the south.

By 221 BCE, he had reestablished Seleucid control over the eastern provinces and taken Anatolia back from his rebellious uncle Achaeus.

The ambitious king turns his eyes toward Syria and Egypt.Egypt has been significantly weakened by court intrigue and public unrest.

The rule of the newly inaugurated Ptolemy IV Philopator (reigned 221-204 BCE) begins with the murder of queen-mother Berenice II.

The young king quickly falls under the absolute influence of imperial courtiers.

His ministers use their absolute power in their own self-interest, to the people's great chagrin.Antiochus seeks to take advantage of this chaotic situation.

After an invasion in 221 BCE had failed to launch, he finally begins the Fourth Syrian War in 219.