The death of Egypt’s Hellenistic king Ptolemy…

The death of Egypt’s Hellenistic king Ptolemy IV in 204 BCE had been followed by a bloody conflict over the regency as his heir, Ptolemy V, was only a child.

The conflict had begun with the murder of the dead king's wife and sister Arsinoë by the ministers Agothocles and Sosibius.

The fate of Sosibius is unclear, but Agothocles seems to have held the regency for some time until he is lynched by the volatile Alexandrian mob.

The regency is passed from one adviser to another, and the kingdom is in a state of near anarchy.

Seeking to take advantage of this turmoil, Antiochus III stages a second invasion of Coele-Syria.

He makes an agreement with Philip V of Macedon to conquer and share the Ptolemies' non-Egyptian territories, although this alliance does not last long.

Antiochus quickly sweeps through the region.

After a brief setback at Gaza, he delivers a crushing blow to the Ptolemies at the Battle of Panium near the head of the River Jordan, which earns him the important port of Sidon.

Seleucid power disintegrates, although the conquest of Coele Syria (Lebanon) and Palestine by Antiochus III (200) and a brief occupation of Armenia make up to some extent for the first defeat of the Seleucids by the Romans and the attendant loss of much of Anatolia.

By this time, the Aegean Greek cities have thrown off the Seleucid yoke, Cappadocia and Attalid Pergamon have achieved independence, and other territories have been lost to the Celts and to Pontus and Bithynia.

Roman emissaries come to Philip and Antiochus in 200 BCE, demanding that they refrain from invading Egypt.

The Romans will suffer no disruption of the import of grain from Egypt, key to supporting the massive population in Italy.

As neither monarch had planned to invade Egypt itself, they willingly comply to Rome's demands.

Antiochus completes the subjugation of Coele-Syria in 198 BCE and goes on to raid Ptolemy's remaining coastal strongholds in Caria and Cilicia.

Problems at home lead Ptolemy to seek a quick and disadvantageous conclusion.

The nativist movement, which had begun before the war with the Egyptian Revolt and expands with the support of Egyptian priests, creates turmoil and sedition throughout the kingdom.

Economic troubles lead the Ptolemaic government to increase taxation, which in turn feeds the nationalist fire.

Ptolemy, in order to focus on the home front, signs a conciliatory treaty with Antiochus in 195 BCE, leaving the Seleucid king in possession of Coele-Syria and agreeing to marry Antiochus' daughter Cleopatra I.

The Roman–Syrian War (192–188 BCE), also known as the War of Antiochos or the Syrian War, is the consequence of a "cold war" between both powers, which had started in 196 BCE.

Romans and Seleucids in these years have tried to settle spheres of influence by making alliances with the Greek minor powers.

The fighting takes place in Greece, the Aegean Sea and Asia Minor.

The Seleucid domains by 190 are limited to Mesopotamia, western Iran, and a landlocked Syria.