Wasn´t the battle of Raphia in 217 BC the turningpoint at which the Ptolemaic army used great contingent of egyptian troops? I think until then at least the phalanx line was mainly composed of Macedonian soldiers. This would have been quite a force on which you could base a rebellion. But I´m not sure if they were so loyal to the house of Ptolemaios, or if they were more like mercenaries, fighting for those who had more money and the greater possibility of winning?
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