What happened 217 AD

Caracalla was assassinated while en route to a campaign against the Parthians by the Praetorian Guard.

On April 8, 217, Caracalla was assassinated traveling to Carrhae. Three days later, Macrinus was declared Augustus. Diadumenian was the son of Macrinus, born in 208. He was given the title Caesar in 217, when his father became augustus, and raised to co-Augustus the following year.

Achaeus returned from his victorious campaign in 217 BC and hostilities between the two resumed.

Ptolemy IV continued this tradition by holding his own synod at Memphis in 217 BC, after the victory celebrations of the Fourth Syrian War.

After the Battle of Raphia in 217 BC, Ptolemaic power became increasingly unstable. There were uprisings among segments of the Egyptian population and, in the first half of the second century BC, connection with Upper Egypt became largely disrupted. Ptolemaic rulers also began to emphasize the Egyptian aspect of their nation over the Greek aspect. Consequently, many Greek scholars began to leave Alexandria for safer countries with more generous patronages.

Although initially unsuccessful in the Fourth Syrian War against Egypt, which led to a defeat at the Battle of Raphia (217 BC), Antiochus would prove himself to be the greatest of the Seleucid rulers after Seleucus I himself.

The Battle of Lake Trasimene was fought when a Carthaginian force under Hannibal ambushed a Roman army commanded by Gaius Flaminius on 21 June 217 BC, during the Second Punic War.

The result of this synod was the Raphia Decree, issued on 15 November 217 BC and preserved in three copies.