Classical writers depict Ptolemy IV as a drunken, debauched reveler, completely under the influence of his disreputable associates, among whom Sosibius is the most prominent.

Cleomenes, imprisoned by Ptolemy, escapes in 219 and, after failing to raise a revolt in Alexandria, takes his own life.

Antiochus, following the defection of one of Ptolemy’s best commanders, is now free to conduct what will be called the Fourth Syrian War (219–216), and seriously threatens Egypt’s Syro-Palestinian territory, Coele Syria.

When the Seleucid ruler in 219 captures the important eastern Mediterranean sea ports of Seleucia-in-Pieria, Tyre, and …

…Ptolemais, …

…Ptolemy's disreputable associate Sosibius and the Ptolemaic court enter into delaying negotiations with the enemy, while the Ptolemaic army is reorganized and intensively drilled.

The threat that is sufficiently grave that, for the first time under the Ptolemaic regime, native Egyptians are enrolled into the infantry and cavalry and trained in phalanx tactics.

Philip soon wins renown by supporting the Hellenic League in its war against Sparta, Aetolia, and Elis (219-217).

The peace with Illyria thus broken, the Romans respond quickly and send Lucius Aemilius across the Adriatic in 219 to besiege Dinale and Pharos, two cities fortified by Demetrius.

Dinale, heretofore regarded as impregnable, falls after seven days.

Aemilius detaches twenty of his ships to make a show in Pharos' harbor, while the rest of the fleet secretly lands its troops behind the town.

Demetrius sends his garrison out to meet the perceived threat of the twenty ships, and at this time the concealed Romans attack his rear.

Caught between two Roman armies, Pharos surrenders within twenty-four hours; Demetrius flees to his benefactor Philip V of Macedon, and the conditions established in 228 again prevail.

The Romans return to Italy to face Hannibal, leaving unscathed Demetrius' ally Scerdilaidas and concluding the Second Illyrian War.

Queen Teuta had submitted to Rome in 228 BCE, but the Illyrian kingdom of the interior had not been destroyed, and the Romans in 219 BCE send a second naval expedition against Illyria, in which their forces overrun the Illyrian settlements in the Neretva River valley and …

…force Illyrian rulers to pay tribute.

Hannibal has spent the past two years of his command consolidating his holdings and completing the conquest of Hispania south of the Ebro.

However, Rome, fearing the growing strength of Hannibal in Iberia, makes an alliance with the Hellenized Iberian coastal city of Saguntum, which lies a considerable distance south of the River Ebro and claims the city as its protectorate.

After great tension within the city government, culminating in the assassination of the supporters of Carthage, Hannibal lays siege to the city in 219 BCE.

The city calls in vain for Roman aid, band following a prolonged eight month siege and a bloody struggle, in which Hannibal himself is wounded and the army practically destroyed, the Carthaginians finally take control of the city.

Many of the Saguntians choose to commit suicide rather than face subjugation by the Carthaginians.

Livy reports that it was agreed in the treaty that the Iber should be the boundary between both empires and that the liberty of the Saguntines should be preserved.

Rome demands justice from Carthage.

In view of Hannibal's great popularity, the Carthaginian government does not repudiate Hannibal's actions, and the war he seeks is declared at the end of the year.

Having thus punctuated the long apprenticeship under his father and brother-in-law, Hannibal now determines to carry the war into the heart of Italy by a rapid march through Hispania and southern Gaul.

The Syrio-Egyptian negotiations collapse in 218 BCE and Antiochus renews his advance, overrunning Ptolemy's forward defenses.

The Seleucids now hold Coele Syria (Lebanon), Phoenicia, and Palestine.