The First Pharaoh Aha (Mens - Menes) or Narmer
All Egyptian historiographical sources unanimously agree that Menes was the first pharaoh. A virtual confirmation of this is provided by the famous Palermo Stone. The upper part (register) only lists the names, in a rather imaginative form, of rulers about whom the writer was evidently unable to provide any other information.

The second register certainly should have begun with Menes, but the part relating to him has been lost; by analogy with the other two kings of the 1st Dynasty mentioned in the large fragment from Cairo, it can be almost certainly assumed that both his Horus name and personal name were included, presumably accompanied by that of his mother.
Under the heading, the spaces reserved for dating undoubtedly recorded year by year the most important events of his reign, although it is likely that the compiler, dealing with such a distant era, may have partly relied on his imagination. It would be interesting to know whether the unification of the Two Lands, which was for the Egyptians the memorable event marking the beginning of humanity’s history, was explicitly mentioned.
An allusion to this event can be found in the expression "Union of Upper and Lower Egypt"; the turning of the walls that marks the first year of reign for every ruler in the Palermo Stone and other documents, which evidently refers to the ceremony with which the ruler’s descent from the founder of the dynasty was legitimized.
The walls mentioned should be those of Memphis, the foundation of which is attributed to Menes by Herodotus and, with some confusion, also by Diodorus Siculus. The Rosetta Stone, regarding Memphis, speaks of the rites regularly performed by the king when assuming his high office.
The move of the royal residence from an unknown location in the South to this city with its superb natural position at the apex of the delta must therefore be considered a direct consequence of the establishment of the dual kingdom.
Other important acts attributed to Menes by Herodotus concern the creation of a dam to protect Memphis from the Nile floods and the construction of the temple of Ptah south of the city's walls; the latter event receives implicit confirmation from a tablet of the 19th Dynasty that names the Ptah of Menes.
As can be imagined, due to the scarcity of historical artifacts and the imperfect understanding of the hieroglyphs of the period, the identification of a king of the 1st Dynasty is never precise or certain. Thus, Menes is identified by some scholars with Narmer, while according to others, he and Aha are the same person.
Finally, some believe that Narmer, Menes, and Aha were three distinct individuals.