A revised new date has been offered for Tirkahah's reign. It is well-known that he had several wars with Esarhaddon king of Assyria, and one or two wars during the first four regnal years of Assurbanipal. The absolute dates are a function of Esarhaddon's reign that has been previously placed by several authorities in 681-669 BCE, without having considered reliable dates such as astronomically confirmed eclipse observations as follow:
Three eclipse observations have been ignored from the reign of Esarhaddon who reigned from 695 to 682 BCE. The Esarhaddon Chronicle has recorded that the sun darkened its light in the month Teshri, in the first year of Esarhaddon (Sidney Smith, Babylonian historical texts relating to the capture and downfall of Babylon, London: Methuen, 1924: 14). This solar eclipse occurred on October 10, 695 BCE. There was a second eclipse in his sixth regnal year: Kudurru wrote that after the king went to Egypt, an eclipse took place in the month Tammuz (Letter 276 in Leroy Waterman, Royal correspondence of the Assyrian empire, Vol. 1, 1930-1936: 187). This eclipse has been confirmed by the book of A.T. Olmstead, A history of Assyria (1923). Our date corresponds to July 18, 690 BCE. Finally, the scribe Akkulanu has reported to Esarhaddon that when the sun arose, it came to pass that an eclipse took place of about two fingers in width. According to a professor of astronomy, it meant that two twelfth of the sun had been darkened and that the only possible date for this eclipse from those decades is November 10, 687 BCE.
Kenneth A. Kitchen in The Third Intermediate Period in Egypt (1973: 380-391) tells a lot about Tirhakah or Taharqa, confirming his highest regnal date as 26 years. He was brother of Shabako or Sebaq-tawy, the previous king of Egypt. Tirhakah may have been only a prince and a military leader and not yet a king when Sennacherib threathened Jerusalem (724 BCE in our revised chronology). See more details under Hezekiah and 2 Kings 19: 9). Tirhakah was the Cushite (i.e., from Nubia or Soudan) king who marched against Sennacherib's Assyrians but apparently turned back. One of Esarhaddon's invasions of Egypt apparently took place in the 17th regnal year of Tirhakah, but he defeated the Assyrians. In his 20th year another Assyrian invasion occurred, then two years later another one, during which Esarhaddon died on his way. Assurbanipal lead a punishing expedition against Tirhakah but he fled to Thebes. His successor was Tantamani.
Kitchen (1973: 181) adds an important detail about the problems of Egyptian chronology at this point. The chronicle of Prince Osorkon mentions a lunar eclipse in Year 15 of the Egyptian King Takeloth II. He observes that 822 BCE is not working, because of the irreducuble total of 106 years from the 15th year of Takeloth II to the 38th and death of Shoshenq V (11+52+6+37 years). Reckoned from 822 BCE they run down to 716 BCE, far too late, because by 712 at the very latest, he says, Shabako was ruler of all Egypt and Nubia. In our revised chronology, this total eclipse of the moon took place on March 16, 851 BCE, a few days from a disastrous mutiny. The latter was dated by Egyptian dates, and gives this as the only probable candidate.