The first "Great King of the West" was Osorkon, although only Piccione has any dates for his reign.(760-740). There is no indication that he ruled Egypt as Pharaoh.

However, his successor Tefnakhte attempted to expand his reign over Egypt from the small city of Sais. He is considered the first Egyptian king of the 24th Dynasty. Not only does he give himself royal titles and call himself a prophet, he is called "Chief of the West" and "Chief of Sais". He managed to unify many of the nomes in the Delta and was considerably more powerful than any of the rules in the 22nd Dynasty or 23rd Dynasty, which had power broken up among many minor rulers.

He headed a coalition of princes from the Delta (Osorkon IV, Iuput II, Sheshonq V) to attack Hermopolis under Nimlot III. Eventually, Tefnakhte was forced to make peace with Nimlot III. He attempted to conquer Herakleopolis and was forced to flee from Piankhe. However, after Piankhe retreated to Napata, he consolidated his rule over much of the Delta.

It is usually assumed that his strong drive to expand control over Egypt is responsible for the invasion.

pharaohs

Osorkon
Tefnakhte I
Bakenranef
Padinemti
Tefnakhte II