Antiochus III the Great in the context of "Battle of Raphia"

Philip V (Greek: Φίλιππος, romanized: Philippos; 238–179 BC) was king of the ancient Greek kingdom of Macedon from 221 to 179 BC. Philip's reign was principally marked by the Social War in Greece (220-217 BC) and a struggle with the emerging power of the Roman Republic. He would lead Macedon against Rome in the First (212-205 BC) and Second (200-196 BC) Macedonian Wars. While he lost the latter, Philip later allied with Rome against Antiochus III in the Roman-Seleucid War. He died in 179 BC from illness after efforts to recover the military and economic condition of Macedonia and passed the throne onto his elder son, Perseus of Macedon.

The Battle of Thermopylae took place on 24 April 191 BC. It was fought as part of the Roman–Seleucid War, pitting forces of the Roman Republic led by the consul Manius Acilius Glabrio against a Seleucid-Aetolian army of Antiochus III the Great.

When the main bodies of the armies initially clashed at the Thermopylae pass, the Seleucids managed to hold their ground, repulsing multiple Roman assaults. However, a small Roman force under Marcus Porcius Cato managed to outflank the Seleucids from the hillside after surprising the Aetolian garrison of Fort Callidromus. The Seleucids panicked and broke ranks, leading to the destruction of their force. Antiochus managed to escape the battlefield with his cavalry, departing mainland Greece soon afterwards.

The Battle of Magnesia took place in either December 190 or January 189 BC. It was fought as part of the Roman–Seleucid War, pitting forces of the Roman Republic led by the consul Lucius Cornelius Scipio Asiaticus and the allied Kingdom of Pergamon under Eumenes II against a Seleucid army of Antiochus III the Great. The two armies initially camped northeast of Magnesia ad Sipylum in Asia Minor (modern-day Manisa, Turkey), attempting to provoke each other into a battle on favorable terrain for several days.

When the battle finally began, Eumenes managed to throw the Seleucid left flank into disarray. While Antiochus' cavalry overpowered his adversaries on the right flank of the battlefield, his army's center collapsed before he could reinforce it. Modern estimates give 10,000 dead for the Seleucids and 5,000 killed for the Romans. The battle resulted in a decisive Roman-Pergamene victory, which led to the Treaty of Apamea that ended Seleucid domination in Asia Minor.

The Roman–Seleucid war (192–188 BC), also called the Aetolian war, Antiochene war, Syrian war, and Syrian-Aetolian war was a military conflict between two coalitions, one led by the Roman Republic and the other led by the Seleucid king Antiochus III. The fighting took place in modern-day southern mainland Greece, the Aegean Sea, and Asia Minor.

The war was the consequence of a "cold war" between both powers, which had started in 196 BC. In this period, the Romans and the Seleucids attempted to settle spheres of influence by forging alliances with the small Greek city-states. Also important were the Romans and Seleucids' irreconcilable visions for the Aegean: the Romans saw Greece as their sphere of influence and Asia Minor as a buffer area while the Seleucids saw Asia Minor as a core part of their empire with Greece as the buffer zone.

The Seleucid dynasty or the Seleucidae (/sɪˈluːsɪˌdiː/; Greek: Σελευκίδαι, Seleukídai, "descendants of Seleucus") was a Macedonian Greek royal family, which ruled the Seleucid Empire based in West Asia during the Hellenistic period. It was founded by Seleucus I Nicator, a general and successor of Alexander the Great, after the division of the Macedonian Empire as a result of the Wars of the Successors (Diadochi).

Through its history, the Seleucid dominion included large parts of the Near East, as well as of the Asian territory of the earlier Achaemenid Persian Empire. A major center of Hellenistic culture, it attracted a large number of immigrants from Greece who, encouraged by the Seleucids, formed a dominant political elite under the ruling dynasty. After the death of Seleucus I, his successors maintained the empire's strength establishing it as a Greek power in West Asia; the empire reached its height under emperor Antiochus III. From the mid-second century BC, after its defeat at the hands of the resurgent Parthian Empire, the polity entered a state of instability with slow territorial losses and internecine civil wars. The Seleucids, now reduced to a rump state occupying a small part of Syria succumbed to the Rome's annexation of their territory in 64 BC under Pompey the Great.

A diadem is a crown, specifically an ornamental headband worn by monarchs and others as a badge of royalty.