Necho, Prince of the Delta city of Sais, was installed as ruler by the *Assyrian conqueror *Esarhaddon, who followed a policy of giving limited authority to those native Egyptian princes whom he could trust. Necho became the foremost of these and wielded power not only in Sais but also in Memphis; he went on to possess a large kingdom in the western Delta and to adopt the pharaonic style in his own title. He probably began to rule as a local king in Sais in 672 BC and was confirmed as ruler by *Esarhaddon in 671 BC.
As the chief vassal of the *Assyrians in Egypt, Necho became a prime target for Tanuatamun, the nephew of King *Taharka of the Twenty-fifth Dynasty. On *Taharka's death, Tanuatamun claimed the kingship of *Nubia and of Egypt (664-656 BC), briefly regaining the country from the *Assyrians and their vassals. He sailed northwards to Thebes and eventually went on to the Delta and Memphis where he killed Necho I, whom the *Assyrians had appointed as local ruler. This power was short-lived; *Psammetichus I (son of Necho I) seized control and established himself as king of Egypt and the founder of the Twenty-sixth Dynasty.
Necho I left few monuments; his main role was to enable his descendants to gain power and establish themselves as the native rulers of an independent Twenty-sixth Dynasty.
BIBL. Kitchen, K.A. 3rd Int. pp 145-7;. Yoyotte, J. Nechao. Supplement au Dictionnaire de la Bible, vi, col. 365.
Biographical Dictionary of Ancient Egypt by Rosalie and Antony E. David
Ancient Egypt. A Reference Guide. EdwART. 2011.