Origin of the conflict according to Herodotus
Herodotus describes how Pharaoh Amasis II would eventually cause a confrontation with Persia. According to Herodotus, Amasis was asked by Cyrus the Great or Cambyses II for an Egyptian ophthalmologist on good terms. Amasis seems to have complied by forcing an Egyptian physician into mandatory labor, causing him to leave his family behind in Egypt and move to Persia in forced exile. In an attempt to exact revenge for this, the physician grew very close to Cambyses and suggested that Cambyses should ask Amasis for a daughter in marriage in order to solidify his bonds with the Egyptians. Cambyses complied and requested a daughter of Amasis for marriage.
Amasis, worrying that his daughter would be a concubine to the Persian king, refused to give up his offspring; Amasis also was not willing to take on the Persian empire, so he concocted a deception in which he forced the daughter of the ex-pharaoh Apries, whom Herodotus explicitly confirms to have been killed by Amasis, to go to Persia instead of his own offspring.
This daughter of Apries was none other than Nitetis, who was, as per Herodotus's account, "tall and beautiful." Nitetis naturally betrayed Amasis and upon being greeted by the Persian king explained Amasis's trickery and her true origins. This infuriated Cambyses and he vowed to take revenge for it. Amasis died before Cambyses reached him, but his heir and son Psamtik III was defeated by the Persians.
First, Cyrus the Great signed alliance agreements with the Lydian King Croesus and Nabonidus the Babylonian king in 542 BCE. The actual aim of the agreements was to prevent aid between Egypt and her allies. With both now deprived of Egyptian support, the Persians conquered, first, Croesus's empire in 541 BCE, and, then, the Neo-Babylonian Empire in 539 BCE.
Herodotus also describes how, just like his predecessor, Amasis relied on Greek mercenaries and councilmen. One such figure was Phanes of Halicarnassus, who would later leave Amasis, for reasons that Herodotus does not clearly know, but suspects were personal between the two figures. Amasis sent one of his eunuchs to capture Phanes, but the eunuch was bested by the wise councilman and Phanes fled to Persia, meeting up with Cambyses and providing advice for his invasion of Egypt. Egypt was finally lost to the Persians during the battle of Pelusium in 525 BCE.
Amasis II died in 526 BCE, before the Achaemenid invasion, and was succeeded by Psamtik III, who only ruled for six months. A few days after his coronation, rain fell at Thebes, which was a rare event that frightened some Egyptians, who interpreted this as a bad omen. The young and inexperienced pharaoh was no match for the invading Persians. After the Persians under Cambyses had crossed the Sinai desert with the aid of the Arabians, a bitter battle was fought near Pelusium, a city on Egypt's eastern frontier, in the spring of 525 BCE. The Egyptians were defeated at Pelusium and Psamtik was betrayed by one of his allies, Phanes of Halicarnassus. Consequently, Psamtik and his army were compelled to withdraw to Memphis. The Persians captured the city after a long siege, and captured Psamtik after its fall. Shortly thereafter, Cambyses ordered the public execution of two thousand of the principal citizens, including (it is said) a son of the fallen king.
Psamtik's captivity and subsequent execution are described in The Histories by Herodotus, Book III, sections 14 and 15. Psamtik's daughter and the daughters of all the Egyptian noblemen were enslaved. Psamtik's son and two thousand other sons of noblemen were sentenced to death, in retaliation for the murder of the Persian ambassador and the two hundred crew of his boat. An "old man who had once been the king's friend" was reduced to beggary. All these people were brought before Psamtik to test his reaction, and he only became upset after seeing the state of the beggar.
Psamtik's compassion for the beggar caused him to be spared, but his son had already been executed. The deposed pharaoh was then raised up to live in the entourage of the Persian King. After a while, however, Psamtik attempted to raise a rebellion among the Egyptians. When Cambyses learned of this, Psamtik is reported by Herodotus to have drunk bull's blood and immediately died.
Herodotus also relates the desecration of Ahmose II/Amasis' mummy when the Persian king Cambyses conquered Egypt and thus ended the 26th (Saite) Dynasty:
[N]o sooner did [... Cambyses] enter the palace of Amasis that he gave orders for his [Amasis's] body to be taken from the tomb where it lay. This done, he proceeded to have it treated with every possible indignity, such as beating it with whips, sticking it with goads, and plucking its hairs. [... A]s the body had been embalmed and would not fall to pieces under the blows, Cambyses had it burned.
The Egyptian anthropoid sarcophagi of Sidonian kings Eshmunazar II and that of his father Tabnit were manufactured around the time of the Achaemenid conquest of Egypt. Similar Egyptian sarcophagi, with characteristic plump and squarish broad faces, and smooth unarticulated bodies, are known to have been produced in the area of Memphis, during the reigns of Psamtik II (ca. 595–589 BC) through the reign of Amasis II (570-526 BC).
Sarcophagus of Eshmunazar II
The sarcophagi of the Sidonian kings are thought to have been plundered during the Achaemenid conquest of Egypt, and brought back to Sidon to be reused for royal funerals.
The sarcophagi found in Sidon were originally made in Egypt for members of the Ancient Egyptian elite, but were then transported to Sidon and repurposed for the burial of Sidonian kings. The manufacture of this style of sarcophagi in Egypt ceased around 525 BC with the fall of the 26th dynasty, therefore Elayi posits that the sarcophagi were seized and brought to Sidon by the Sidonians during their participation in Cambyses II's Achaemenid conquest of Egypt in 525 BC.
Wheareas the Tabnit sarcophagus, belonging to the father of Eshmunazar II, reemployed a sarcophagus already dedicated on its front with a long Egyptian inscription in the name of an Egyptian general, the sarcophagus used for Eshmunazar II was new and was incribed with a full-length dedication in Phoenician on a clean surface. According to René Dussaud, the new sarcophagus may have been ordered by his surviving mother, Queen Amoashtart, who arranged for the inscription to be made.
The sarcophagi were probably, at least in part, captured as booty by the Sidonian Kings. Herodotus does recount an event in which Cambyses II "ransacked a burial ground at Memphis, where coffins were opened up and the dead bodies they contained were examined", quite possibly providing the occasion on which the sarcophagi were removed and reappropriated by his Sidonian subjects. This is especially the case of the sarcophagus of Tabnit, which was already dedicated to a military man named Penptah and may have been desacrated, wheareas the unfinished, not yet dedicated, sarcophagus of Eshmunazar may have been obtained from a Memphis workshop.
These sarcophagi (a third one probably belonged to the Queen Amoashtart), are the only Egyptian sarcophagi that have ever been found outside of Egypt proper.