Egypt's Internal Breakdown

The last really masterful king of independent Egypt was Ramesses III. During and following his rule the breakdown of Egypt was apparent. Ramesses III was almost certainly murdered. Judicial investigation revealed a conspiracy throughout the court, administration and army. Kings who succeeded were shadowy, ephemeral figures. In Ramesses III's lifetime, elite workers strike at the royal necropolis, because they weren't being paid, suggests corruption within administration. A mid-twentieth Dynasty papyrus reveals dishonest dealings among senior clergy in the Temple of Khnum at the First Cataract and another papyrus describes the looting of the royal tombs on the West Bank at Thebes under Ramesses IX (about 1142-1123 BC)
Other tomb-robbing crimes went on and the state could not stop the robberies. The authorities resorted to hiding the mummies in other places so they would be protected. Foreign bandits, described as Libyans appeared. Riots, mutinies and popular unrest were common throughout Egypt. Egypt ran out of metals, especially gold, and could not pay its mercenaries. State employees and high officials took their pay from the royal tombs.
The state could not afford to pay mercenary armies and lost a great deal of power. The church gained more power than the pharaoh because they had more money.
Money and public dissent were not Egypt's only problems, however. Its internal unrest made Egypt easily susceptible to attack from the outside.
Kushite's (also known as the Nubians) and Assyrian's took over around 656 BC and from 535-404 BC Egypt became a province of the Persian empire. Egypt then gained independence from Persia, but it could only hold its independence with the help of the Greeks.
The post-Persian Egypt lived in fear of Persian dominance and depended greatly on the Greeks. Egypt didn't have enough money to pay the Greeks, however.
In 380 BC Control was passed to a military officer named Nectanebo I, the first king of Dynasty XXX. His son, Teôs, was the next ruler. Teôs had a bad military strategy and he launched an attack on Phoenicia, which was weakened by a feud between him and the commander of his mercenaries; 80 year old Spartan king, Agesilaus. Teôs taxed the public and became very unpopular. The army ended up deserting him to the King's nephew, Nectanebo II, the next ruler.
Nectanebo II was the last native ruler of Egypt. Persian invasions, and revolts by the satraps of Phoenicia persisted throughout his rule. Artaxerxes Ochus attacked the frontier city of Pelsium with an army three times that of Nectanebo. But Persian rule was short, in 330 BC Alexander of Macedon entered Egypt and became Pharaoh. Egypt became a province of the Hellenistic world and its independent kingdom was at an end.