Sometime between October and December 222 BC, Ptolemy III died and Ptolemy IV was crowned king. The new king was about twenty years old and was under the strong influence of two prominent aristocrats:
Sosibius and
Agathocles, the brother of Ptolemy IV's mistress
Agathoclea. On Ptolemy IV's accession, Sosibius engineered a large-scale purge of the royal family in order to eliminate anyone who might be able to oppose him. Ptolemy IV's uncle
Lysimachus was probably murdered at this time. His mother Berenice II was believed to support his younger brother Magas, who had held substantial military commands and was popular with the army, so Magas was scalded to death in his bath. By contrast, Ptolemy IV's older sister,
Arsinoe III, was brought into close association with the king. They had married by 220 BC;
sibling marriage was a common practice among Egyptian royal families, including the Ptolemies.
Fourth Syrian War (219–217 BC) In 222 BC,
Antiochus III had assumed the Seleucid throne and he instantly proved a dynamic leader, determined to restore Seleucid power and to reverse the losses that the Seleucids had suffered in the Third Syrian War. In 221 BC, one year after his accession, Antiochus III invaded the Ptolemaic territories in
Coele-Syria. He was rebuffed by the Ptolemaic governor of the region,
Theodotus, and forced to turn east as a result of the revolt of his satrap of
Media,
Molon. In spring 219 BC, Antiochus III tried again, attacking and capturing the key port city and 'hearth of the Seleucid dynasty'
Seleucia Pieria, which had been under Ptolemaic control since 246 BC. Immediately after this, Theodotus, who had become unpopular at the Ptolemaic court, switched to the Seleucid side, bringing Coele Syria and a large portion of the Ptolemaic fleet with him. Antiochus III received the surrender of
Tyre and
Ptolemais Ake, but he became bogged down in protracted sieges of
Sidon and
Dora. Antiochus III's efforts to consolidate his control over Coele Syria lasted for the rest of 219 BC. At the beginning of winter, he had to negotiate a ceasefire with Ptolemy IV. Formal peace negotiations followed at Seleucia Pieria, but they do not seem to have been undertaken in good faith on either side. Antiochus refused to consider returning Seleucia Pieria to the Ptolemies, while Ptolemy IV demanded that Antiochus III recognise
Achaeus, the
de facto ruler of Asia Minor, who was considered a rebel by the Seleucid court, as a party to the piece. He had much less success in his attempts to negotiate a peace between the Macedonia and the
Roman Republic in the
First Macedonian War (215–205 BC). Ptolemy IV made large financial contributions to a number of Greek cities in order to gain their favour. He was responsible for the city walls at
Gortyn in
Crete Ptolemy was honoured for his benefactions with monuments and cults in his honour at various cities, including
Rhodes and
Oropus In the west, Ptolemy maintained friendly neutrality with the Roman Republic and
Carthage, which were fighting against one another in the
Second Punic War (218-201 BC). He received a friendly embassy from the Romans in 210 BC, requesting a gift of grain to help feed the starving populace. It is unknown how Ptolemy responded to this request. Like his predecessors, Ptolemy IV maintained particularly close relations with the kingdom of Syracuse under King
Hiero II, but the accession of Hiero II's grandson
Hieronymus in 215 BC threatened to upset the careful balance that Ptolemy IV had maintained. Hieronymus repeatedly tried to bring the Ptolemies into the Second Punic War on the Carthaginian side. The situation was resolved with his assassination in 214 BC.
Egyptian Revolt and death (206–204 BC) Sometime after the end of the Fourth Syrian War, revolts broke out in Egypt itself. Fighting took place in the north of the country in the
Delta and separately in
Upper Egypt, where fighting led to the interruption of building work on the Temple of Horus at
Edfu in 207–206 BC. The reasons for these revolts are unclear. The Hellenistic historian
Polybius argued that they were a natural result of Ptolemy IV's decision to arm the Egyptians during the Fourth Syrian War.
Günther Hölbl argues that the fact that the rebels attacked Egyptian temples suggests that it was "a rebellion of the lower classes inspired by social injustice," that had been exacerbated by the heavy taxation necessary to fund that war. In October or November 205 BC, the leader of the southern revolt captured the city of
Thebes and had himself crowned
Pharaoh, taking the name Horwennefer, rendered in Greek sources as
Hugronaphor. Despite Ptolemaic efforts to suppress his regime, Horwennefer would retain his independence for nearly twenty years, until finally captured in August 186 BC. The revolt meant that Ptolemaic forces were unable to defend southern Egypt from
Nubian incursions. Probably in 207–06 BC, King
Arqamani of
Meroe seized control of the
Dodecaschoenus. A number of the temple building projects that had been undertaken in this region were completed by Arqameni or his successor
Adikhalamani. In many cases, the work of Ptolemy IV was simply appropriated by erasing his name from inscriptions and replacing it with that of Arqameni. ==Regime==