thumb|upright=0.6|Libyan soldier of the Achaemenid army, . Xerxes I tomb relief. In 525 BCE the Persian army of Cambyses II overran Cyrenaica, which for the next two centuries remained under Persian or Egyptian rule. Alexander was greeted by the Greeks when he entered Cyrenaica in 331 BCE, and Eastern Libya again fell under the control of the Greeks, this time as part of the Ptolemaic Kingdom. Later, a federation of the Pentapolis was formed that was customarily ruled by a king drawn from the Ptolemaic royal house.
thumb|upright=06|libyan soldier of the achaemenid army  xerxes i tomb relief in 525 bce the persian army of cambyses ii overran cyrenaica which for the next two centuries remained under persian or egyptian rule alexander was greeted by the greeks when he entered cyrenaica in 331 bce and eastern libya again fell under the control of the greeks this time as part of the ptolemaic kingdom later a federation of the pentapolis was formed that was customarily ruled by a king drawn from the ptolemaic royal house