Many readers of the Bible are puzzled to know why all the kings of Egypt are called Pharaoh, only three of them, Necho, Shishank and Hophrah, being known by any other name in the Scriptures. The meaning of the word, and its use by the Egyptians as a title, are explained by Brugsch Bey in the following passage from his "Egypt Under the Pharaohs":

      The Memphite tombs tell much concerning the customs of Pharaoh and his court. The sovereign bears the official title of "King of the Upper and Lower Country;" he is also called Perao, "the great house;" better known, perhaps, under the Hebrew equivalent of Pharaoh. The people honored him as "lord" (neb) and "god" (neter). At sight of him every native prostrated himself and touched the ground with his nose, and it was an especial favor if the command of his lord permitted him to kiss his knee (p. 23).

      It seems, from this, that the Hebrews adopted one of the current Egyptian titles of the king as their habitual name for him, spelling and pronouncing it according to the idiom of their own tongue. While all of these kings had each his own personal name, it was not common, even in Egypt, to use it in speaking of him, the more complimentary titles being preferred. We have similar [120] usages in modern times. For instance, it is very rarely that we see the name Abdul Hamid applied to the present ruler of Turkey; or Alexander applied to the ruler of Russia. Instead of this, we almost uniformly speak of the one as the Czar and the other as the Sultan. In reality, our English Bibles ought to read, in every instance, instead of Pharaoh, the Pharaoh; for then the title, as in the cases of the Czar and the Sultan, would not be taken by the uninformed reader as a personal name.

[SEBC 120-121]