Consequently, pharaoh Taharqa's reign, and that of his successor Tantamani, were filled with constant conflict with the Assyrians. In 664 BC the Assyrians delivered a mortal blow, sacking Thebes and Memphis. Following these events, and starting with Atlanersa, no Kushite ruler would ever rule over Egypt again. End of the Third Intermediate Period Upper Egypt remained for a time under the rule of Taharqa and Tantamani, whilst Lower Egypt was ruled from 664 BC by the nascent 26th Dynasty, client kings established by the Assyrians. In 663 BC, Tantamani launched a full-scale invasion of Lower Egypt, taking Memphis in April of this year, killing Necho I of Sais in the process as Necho had remained loyal to Ashurbanipal. Tantamani barely had the time to receive the submission of some Delta kinglets and expel the remaining Assyrians that a large army led by Ashurbanipal and Necho's son Psamtik I came back. Tantamani was defeated north of Memphis and Thebes was thoroughly sacked shortly after. The Kushite king withdrew to Nubia while the Assyrian influence in Upper Egypt quickly waned. Permanently weakened by the sack, Thebes peacefully submitted itself to Psamtik's fleet in 656 BC. To affirm his authority, Psamtik placed his daughter in position to be the future Divine Adoratrice of Amun, thereby also submitting the priesthood of Amun and effectively uniting Egypt. Tantamani's successor Atlanersa was in no position to attempt a reconquest of Egypt as Psamtik also secured the southern border at Elephantine and may even have sent a military campaign to Napata. Concurrently, Psamtik managed to free himself from the Assyrian vassalage while remaining on good terms with Ashurbanipal, possibly owing to an ongoing rebellion in Babylon. By doing so, he brought increased stability to the country during his 54-year reign from the city of Sais. Four successive Saite kings continued guiding Egypt into another period of peace and prosperity from 610 to 525 BC. Unfortunately for this dynasty, a new power was growing in the Near East – the Achaemenid Empire of Persia. Pharaoh Psamtik III had succeeded his father Ahmose II for only 6 months before he had to face the Persian Empire at Pelusium. The Persians had already taken Babylon and Egypt was no match for them. Psamtik III was defeated and briefly escaped to Memphis, before he was ultimately imprisoned and, later, executed at Susa, the capital of the Persian king Cambyses, who now