Piankhi (or Piye) of the Twenty-Fifth Dynasty ascended the Nubian (Kushite) throne as the successor of Kashta.
Piankhi started his reign from Napata; and extended his control to the north as far as Thebes, besides having nominal control over the princes of Middle Egypt.
He then fought Tefnakhte, the Twenty-Fourth Dynasty king who ruled in Lower Egypt, and forced him to take refuge in the swamps of the Delta.
As a way to maintain religious power in Egypt, Piankhi forced the "Divine Adorer of Amun", Shepenwepet, daughter of Osorkon the Third of the Twenty-Third Dynasty, to adopt his sister, Amunirdis, in order to transmit theocratic power to the hands of the Nubian Dynasty.
All Egypt submitted to Piankhi's rule and he recorded his victories on a stela that is preserved in the Egyptian Museum. He left few monuments in Egypt, other than an expansion of the Temple of Amun at Thebes.
After he had settled the situation in Egypt, Piankhi returned to Napata, possibly because he considered Napata to be his real capital and may have preferred not to rule Egypt personally.
After his departure, Tefnakhte would again claim kingdom and as the founder of the Twenty-Fourth Dynasty, ruling at least the western Delta.
However, later successors to Piankhi would consolidate their control over Egypt, at least for a time.