He ascended the throne around the year 180 BC, but under the full supervision of his mother Cleopatra I until her death. Then he was under the supervision of Euloeus and Lenoeus who were two of the palace's slaves. Reaching the age of fifteen, he was announced in a formal procession at Memphis as the King of Egypt in 172 BC. At that time, he was already married to his elder sister Cleopatra II. At that time, Antiochus IV was ruling Syria, and suffering from different problems with the Jews.
The royal court in Alexandria thought that this was the best time to attack Syria to take back the area of Coele-Syria, and they started preparing the army for a Sixth Syrian War. Each of the two groups sent delegation to explain their position to Rome, and Rome was not very keen to solve their problems, as Rome was getting ready for the Third Macedonian War, and they found that the best thing for them is to keep these two powers threatening each other, so they would not interfere in the war anyway. Antiochus IV moved towards Egypt, and he was crowned as a king at Memphis following the same procession as Alexander the Great which made the people of Alexandria really furious, and they started a great revolution against both Euloeus and Lenoeus. Antiochus IV announced the younger brother of Ptolemy VI as the Ruler of Egypt, since he knew that the people of Alexandria loved him badly, but this was hardly accepted by all the Egyptians, since Ptolemy VI was the legal heir to the throne.
Antiochus IV didn’t find any better solution except leaving both kings ruling. But he had problems in his empire: another revolution took place by the Jews in Palestine, so he was obliged to leave Egypt under the rule of both kings and to go to Palestine. After Antiochus IV solved his problems in Palestine. He decided in 168 BC to return back to Egypt to meet Ptolemy VI to explain to him what happened. At that time, Cleopatra II succeeded in keeping the whole condition stable between the two brothers, and they were ruling together. When Antiochus IV was in his way to Egypt, he conquered Cyprus and reached Alexandria.
The two Ptolemies tried to convince him to go to his own country, but he refused. They didn't find any alternative but to send to Rome asking for its advice. Rome didn't support the idea of Antiochus IV ruling, especially after they won the Third Macedonian War, so they sent Popilus to negotiate with Antiochus IV. Popilus asked him in a very diplomatic way to leave Egypt, and when Antiochus IV asked for a chance to think, Popilus drew a circle on the sand around the legs of Antiochus IV asking him to make his decision before he steps out from the circle. Antiochus IV didn't find any other option except leaving Egypt and shaking Popilus' hands expressing his loyalty to Rome. After the complete backing of Antiochus IV of Egypt, Egypt was greatly loyal to the Romans, since they saved them from Antiochus IV.
Problems started between the two brothers, and they both asked Rome for help. Rome decided to divide Egypt between them as well as the countries under Egypt's control. Philometor ruled Egypt and Cyprus, while the other brother ruled a part of Libya. The younger brother left a will that this should be ruled by Rome after his death. Ptolemy VI announced his elder son, Eupator, as his co-regent in 153 – 152 BC, but this son died suddenly. The condition in Egypt was unstable and it was easy for Antiochus IV to re-conquer Egypt, but he was very busy with his internal affairs until he was killed in war in 145 BC. Philometor announced his second son Naeos Philometor as his co-regent under the supervision of his mother Cleopatra II. Philometor died leaving his youngest son Naeos Philometor under Cleopatra II's supervision.
At that time, Rome started to rule most of the world. Ptolemy VIII (The uncle of Naeos Philometor) wanted to have full control of Egypt through taking the position of Cleopatra II, and he was even ready to spark a war against his sister and nephew to rule Egypt. At that time, Philip V, King of Macedonia, died, and his son Perseus was defeated by the Romans at the Battle of Rydna. Macedonia was then divided into several cities until finally in 147 BC it was reduced into a Roman city.
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