Tefnakht I formed an alliance of the Delta kinglets, with whose support he attempted to conquer Upper Egypt; his campaign attracted the attention of the Nubian king, Piye, who recorded his conquest and subjection of Tefnakhte of Sais and his peers in a well-known inscription. Tefnakht is always called the "Great Chief of the West" in Piye's Victory stela and in two stelas dating to the regnal years 36 and 38 of Shoshenq V. It is uncertain if he ever adopted an official royal title. However, Olivier Perdu has now argued that a certain Shepsesre Tefnakhte of Sais was not, in fact, Piye's famous nemesis. Perdu published a recently discovered donation stela which came from a private collection; the document is dated to Year 2 of Necho I of Sais and is similar in style, epigraphy and text with the donation stela of Shepsesre. However, Perdu's arguments are not accepted by most Egyptologists at present, who believe that the Year 8 Shepsesre Tefnakht Athens stela was most likely Tefnakht I. The later king Tefnakht II, if he existed, would have been a close predecessor of Necho I. Both Tefnakht II and Necho I ruled as local Saite kings during the Nubian era under Taharqa.
Tefnakht I's successor, Bakenranef, definitely assumed the throne of Sais and took the royal name Wahkare. His authority was recognised in much of the Delta including Memphis where several Year 5 and Year 6 Serapeum stelas from his reign have been found. This Dynasty came to a sudden end when Shabaka, the second king of the Twenty-Fifth Dynasty, attacked Sais, captured Bakenrenef and burned him alive.